Objective To identify baseline attributes associated with consecutively missed data collection visits during the first 48 months of Look AHEAD - a randomized, controlled trial in 5,145 overweight/obese adults with type 2 diabetes designed to determine the long-term health benefits of weight loss achieved by lifestyle change. Design and Methods The analyzed sample consisted of 5,016 participants who were alive at month 48 and enrolled at Look AHEAD sites. Demographic, baseline behavior, psychosocial factors, and treatment randomization were included as predictors of missed consecutive visits in proportional hazard models. Results In multivariate Cox proportional hazard models, baseline attributes of participants who missed consecutive visits (n = 222) included: younger age (hazard ratio [HR] 1.18 per 5 years younger; 95% confidence Interval 1.05, 1.30), higher depression score (HR 1.04; 1.01, 1.06), non-married status (HR 1.37; 1.04, 1.82), never self-weighing prior to enrollment (HR 2.01; 1.25, 3.23), and randomization to minimal vs. intensive lifestyle intervention (HR 1.46; 1.11, 1.91). Conclusions Younger age, symptoms of depression, non-married status, never self-weighing, and randomization to minimal intervention were associated with a higher likelihood of missing consecutive data collection visits, even in a high-retention trial like Look AHEAD. Whether modifications to screening or retention efforts targeted to these attributes might enhance long-term retention in behavioral trials requires further investigation. © 2013 The Obesity Society.