Set two years after the first film, the film begins with Carrie (Sarah Jessica Parker), Samantha (Kim Cattrall), Charlotte (Kristin Davis) and Miranda (Cynthia Nixon) meeting up with each other at a shop in New York which turns into a flashback to how Carrie first meets Samantha, Charlotte and Miranda in 1986 in New York City.
The film then jumps to the present, two years after the events of the first film. At the Connecticut same-sex wedding of Stanford Blatch (Willie Garson) and Anthony Marentino (Mario Cantone), Liza Minnelli appears to officiate the wedding vows and sings Beyoncé's "Single Ladies (Put a Ring on It)".
The four friends now have lives that are more stressful than before: All are married except Samantha, who is now 52 and trying to keep her libido alive with hormones while dealing with menopause. Miranda quits her job after the new managing partner disrespects her once too often. Charlotte's two children are a handful and she's worried that Harry is attracted to their buxom Irish nanny, Erin (Alice Eve).
Carrie's marriage to Mr. Big (Chris Noth) has settled down, though they differ on how to spend their spare time: she loves to go out, he would prefer to stay home every night, eating take-out meals and watching television. For their anniversary, Carrie gives Mr. Big a vintage Rolex watch engraved with a romantic message, while he, much to her dismay, shows her a new television in their bedroom as his gift, which Big says they can use to watch old movies together as they did on vacation. Carrie is disappointed, as she had hoped for jewelry as a gift. She asks to spend some personal time alone in her old apartment, but Big enjoys the time to himself even more than she does, and to Carrie's dismay, asks to make it a weekly occurrence.
Meanwhile, Samantha has been approached by an Arab sheikh to devise a PR campaign for his business. He offers to fly her and her friends on an all-expenses-paid luxury vacation to Abu Dhabi. The girls happily accept, although Carrie is worried about the separation from Big and Charlotte is worried about leaving her husband alone with the nanny. Only Miranda, unfettered by a job for the first time in her life, plunges enthusiastically into studying Arabic and planning sightseeing.
Upon entering Abu Dhabi, Samantha's hormone-enhancing drugs are confiscated under UAE law. This renders her devoid of estrogen; to her great dismay, her famous libido goes dead, unaroused even by Australian men in Speedo swimwear. Charlotte tries to call Harry every few minutes. Miranda revels in the luxury surrounding her, while Carrie befriends her manservant, Gaurau (Raza Jaffrey), and learns of his long distance marriage - he can only afford to see his wife back in India once every few months.
While out shopping at the local souk with Miranda, Carrie runs into her former lover, Aidan (John Corbett). He proposes dinner à deux at his hotel, but she is noncommittal. The next day, however, she is crushed at reading a negative critique of her new book in The New Yorker, and decides to meet Aidan for dinner, although Charlotte cautions her not to play with fire. The dinner is very enjoyable, with the two discussing old times. Aidan remarks on the ways Carrie is "not like other women", pointing out that when they were engaged, she would only wear her engagement ring on a chain around her neck; now that she's married, she still isn't wearing a diamond on her ring finger, only her wedding ring. In a moment of remembered passion, they kiss. Carrie runs away in a panic and returns to the hotel.
Meanwhile, back at the hotel, Miranda and Charlotte have drinks together and discuss the difficulties of motherhood. Miranda admits painfully that being a mother is not enough for her and that she misses her job. Charlotte confesses her guilt at enjoying her time away from her daughters and her frustration with trying to be the perfect mother at all times. She drinks so many cocktails to bolster her courage to be honest with Miranda that she becomes very tipsy.
At this point, Carrie bursts into the room, crying, "I played with fire!". After summoning Samantha, she tells her friends about the kiss, and asks them whether or not she should tell Big, as she says they have no secrets between them. Miranda reflects on the events of the previous film, when her husband, Steve (David Eigenberg), told her about his affair and how in retrospect, while it helped clear his conscience, she is not sure that knowing was worth the pain she went through. Charlotte is too drunk to be any help, but Carrie already knows where she stands. Samantha counsels Carrie to wait and sleep on it before deciding anything.
Carrie opts to call Big from Abu Dhabi to tell him. Previously, in the television series, Carrie had had an affair with Big, who was then married to Natasha, while dating Aidan, which subsequently caused both couples to break up. Big is silent upon hearing the news, and after saying a few words, hangs up.
The four women find their style and Western attitudes contrast with Muslim customs, with Samantha facing the most conflict. While on a date with Rikard (Max Ryan), a handsome Dane, Samantha is arrested for public indecency after fondling him at a restaurant and making out with him on the beach (she claims they were just kissing). With the Sheik's intervention, Samantha is released, but is left with a permanent police record. Worse, due to her display of disrespect for local custom, the Sheik cancels the PR meeting and ceases paying for the women's luxurious perks.