Mork Goes Erk

"Mork Goes Erk" is the seventeenth episode of the first season of the American television sitcom Mork & Mindy. The episode aired on ABC on February 8, 1979. It was issued on VHS on January 1, 1998, as part of a two-episode special release that also included "Mork's First Christmas". It was issued on DVD on September 7, 2004, as part of the Mork & Mindy - The Complete First Season boxed set.

The episode was written by Lloyd Turner and Gordon Mitchell and directed by Howard Storm. In the episode, David Letterman portrays a self-help group leader named Ellsworth who offers "erk" (Ellsworth Revitalization Konditioning). The episode has been called a parody of the Erhard Seminars Training, or "est" course. The episode received mostly positive reviews, and was highlighted as one of the season's best episodes. David Letterman's performance also received good reviews.