Objective and Participants: The authors investigated the effect of physical activity (PA), fruit and vegetable intake, and alcohol use on 6-month weight change in 193 college freshmen (78.8% white, 88.2% women, 94.5% on a meal plan). Methods: The authors administered a Web-based survey in fall 2002 (baseline) and spring 2003 (follow-up). Results: There was an overall average weight gain of 2.5 lbs (p less than 0.05), although only 57% reported weight gain (M = 7.1 lbs). Fruit and vegetable intake decreased (p = 0.034), alcohol use increased (p greater than 0.05), and PA was unchanged. Weight gain for students with body mass indexes (BMI) [greater than or equal] 25 kg/m[superscript 2] was nearly twice that of students with BMIs less than 25 (p less than 0.05). Students with low-frequency baseline PA were twice as likely to be overweight. Follow-up data showed that students reporting [greater than or equal] 4 sessions per week (ie, high frequency) of low-intensity PA were twice as likely to have healthy BMIs as students engaging in low- and moderate-frequency PA. Conclusions: PA interventions should target freshmen with BMIs [greater than or equal] 25. (Contains 5 tables.)