This study examined the potential impact of parents on the long-term results of an immersion program for the treatment of adolescent obesity. Teenagers participated in a 4- to 8-week therapeutic camp. Those who continued losing weight 8- to 12-months postcamp were identified as "Losers"; those who regained weight were considered "Gainers." Parents from both groups were interviewed about their own current lifestyle habits 1 to 1.5 years after camp ended. Results indicate that more of the initially overweight parents from the Loser group lost weight during the follow-up period than the overweight parents of Gainers. Losers' parents also reported better implementation of several aspects of the weight control program. The present results suggest that helping parents adopt lifestyle changes for themselves, even within the context of relatively short immersion treatments, may maximize outcomes for obese teenagers. (Contains 4 tables and 3 figures.)