The famous "lost" Christmas episode of I Love Lucy is built around a tacky-looking Yuletide tree that Fred (William Frawley) has bought for the Ricardos. While Lucy (Lucille Ball) spends a goodly amount of time attempting to "improve" the looks of the tree by methodically pruning its branches, Ricky (Desi Arnaz), Fred, and Ethel (Vivian Vance) try to convince Little Ricky (Richard Keith) to go to sleep so that "Santa Claus" will arrive. This slender plotline is used to bookend some choice excerpts from previous I Love Lucy episodes, all drawn from the period in which Lucy was pregnant: "Lucy Is Enceinte, "Lucy's Showbiz Swan Song, and "Lucy Goes to the Hospital." Things come to a surprising end with a rare "supernatural" gag.

Originally telecast but once on CBS, "The Christmas Episode" was never included in the standard I Love Lucy syndicated package; in fact, it did not resurface until December 18, 1989, when CBS presented a new, partly colorized print of the episode as a Christmas special.