| Season | Episode | Airdate | Episode Title | Story Line |
| 04.01 | 68 | 09/20/2001 | The Third Wheel Gets the Grace | When Will returns from vacation, Nathan feels neglected when Will and Grace resume their chummy friendship. Jack, Karen and Rosario take Elliot shopping. |
| 04.02 | 69 | 10/04/2001 | Past and Presents | The new lawyer in Will's firm is the same lout who bullied him as a child; Nathan's birthday flusters Grace, who's outdone in the gift department by Karen. |
| 04.03 | 70 | 10/11/2001 | Crouching Father, Hidden Husband | Softhearted Grace steps out to a prom--with Jack's dateless 12-year-old son; demanding Karen cries wolf to Will once too often. |
| 04.04 | 71 | 10/18/2001 | Prison Blues | When Stan is arrested for tax evasion, Grace moves into Karen's apartment to help her worried friend; Jack's crusty acting coach helps Will face a phobia. |
| 04.05 | 72 | 10/25/2001 | Loose Lips Sink Relationships | Jack arranges a "date"' between his geeky, female supervisor and an ususpecting Will. Meanwhile, things really heat up for Grace and Nathan. |
| 04.06 | 73 | 11/01/2001 | Rules of Engagement | Nathan proposes to Grace, who turns him down and then realizes she's made "a complete mess of a really great thing." |
| 04.07 | 74 | 11/08/2001 | Bed, Bath and Beyond | It's heartbreak city for Grace, who, jilted by Nathan, takes cold comfort in the desperate attempts of Will and company to rally her. |
| 04.08 | 75 | 11/15/2001 | Star-Spangled Banter | Will and Grace elect to disagree when it comes to choosing sides during a mayoral election; she supports the Jewish candidate and he's voting for the gay nominee. |
| 04.09 | 76 | 11/22/2001 | Moveable Feast | Rather than be apart on Thanksgiving Day, Will and Grace join Jack and Karen for a festive holiday motor tour of their respective dysfunctional families. |
| 04.10 | 77 | 12/06/2001 | Stakin' Care of Business | Old and new boyfriends vex Will at his gym, while Jack tries to spread a new saying; a proposed business deal unsettles the friendship between Karen and Grace. |
| 04.11 | 78 | 12/13/2001 | Jingle Balls | During the holidays, Jack's boss Dorleen allows him to decorate a Barney's display window, while Will meets a ballet dancer but is too embarrassed to introduce him to his friends. |
| 04.12 | 79 | 01/10/2002 | Whoa, Nelly | Grace and Will scheme to fix up Will's father's mistress. Jack and Karen buy a horse for breeding, but the stud is more interested in stallions. |
| 04.13 | 80 | 01/17/2002 | Grace in the Hole | A jailbird charms Grace, while a jailhouse-like scenario makes nettlesome roommates of Karen and Jack. |
| 04.14 | 81 | 01/31/2002 | Dyeing is Easy, Comedy is Hard | Grace hauls Will to her ex-fiancé's wedding; Elliot's mother demands that Jack never see his son again. |
| 04.15 | 82 | 02/07/2002 | A Chorus Lie | A flustered Jack turns to Grace to "in" Owen, who's competing against him for a spot in the Manhattan Gay Men's Chorus. Will attends the Walker's annual Valentine's Day party. |
| 04.16 | 83 | 02/28/2002 | Someone Old, Someplace New | Apartment hunting busies Will and Grace; prying into Karen's mysterious past preoccupies Jack. |
| 04.17 | 84 | 03/07/2002 | Something Borrowed, Someone's Due | Will and Grace move into their dream apartment, but find that they miss their old one; Karen's mother recruits her for one last scam. |
| 04.18 | 85 | 03/28/2002 | Cheatin' Trouble Blues | Will presents his newly reconciled parents with a cruise for their anniversary, but their individual secrets ruin his hopes. |
| 04.19 | 86 | 04/04/2002 | Went to a Garden Potty | Grace accidentally beheads Will's beloved garden gnome; Jack plays it straight for a mattress TV ad. |
| 04.20 | 87 | 04/11/2002 | He Shoots, They Snore | Chaperoning Jack's son occupies Will at Elliot's basketball tourney; teaching a design seminar challenges Grace. |
| 04.21 | 88 | 04/18/2002 | Wedding Balls | Grace plans a wedding for Will's friend; Jack becomes jealous of Karen and Will's book club. |
| 04.22 | 89 | 04/25/2002 | Fagel Attraction | Will's laptop computer is stolen and a detective promises to help him find it; Meanwhile, psycho neighbor Val opens a rival design business; and Jack takes part in gay group therapy. |
| 04.23 | 90 | 05/02/2002 | Hocus Focus | Will and Grace win a photo session with a famous photographer. Meanwhile, Karen helps Jack with his new magic show. |
| 04.24 | 91 | 05/09/2002 | A Buncha White Chicks Sittin' Around Talkin' | Parenthood prospects fluster Will and Grace, who consider having a baby; a conjugal visit vexes Karen; a Broadway audition rattles Jack. |
| 04.25 | 92 | 05/16/2002 | A.I.: Artificial Insemination | Obstacles pile up before Will and Grace's baby-making plans. Meanwhile, Jack considers giving up show-business and Karen is tempted by a smooth-talking man-about-town. |