Purpose. To examine the effect of mindfulness meditation and home-based resistance exercise when added to a standard behavioral intervention on weight loss, weight loss behaviors, and various psychosocial correlates in overweight adults across 6-months. Methods. Seventy-one subjects (BMI = 32.9±3.7 kg/m²; age = 45.1±8.3 years) participated in a 6-month weight loss intervention. Subjects were randomly assigned to one of three treatment groups: standard behavioral weight loss program (SBWL, n=24), SBWL plus resistance exercise (RT, n=23), or SBWL plus mindfulness training (MD, n=24). Participants were instructed to decrease energy intake to 1200–1500 kcal/d and dietary fat intake to 20–30% of total energy intake, increase physical activity to 300 min/wk, and attend weekly group meetings. Resistance training using resistance tubing and exercise balls was added to SBWL+RT. SBWL+MD consisted of mindfulness training using meditation, yoga, and mindful eating techniques. Body weight, process measures of weight loss (physical activity, energy intake, eating behavior inventory), and psychosocial correlates of weight loss (eating and physical activity self-efficacy, outcome expectations (benefits) and barriers to exercise, dietary restraint and disinhibition, and body image) were measured at 0, 3, and 6 months. Results. Weight significantly decreased in all groups at 6 months (p<0.05), but did not differ between groups (SBWL=−6.1±2.4 kg; SBWL+RT=−8.8±1.9 kg, SBWL+MD=−8.0±0.2 kg). Physical activity (833±439 kcal/wk) and weight loss eating behaviors increased (p<0.05) with no significant difference between groups. Physical activity and eating self-efficacy, dietary restraint, and most subscales of body image increased over the 6-month intervention, while dietary disinhibition, perceived hunger, and overall exercise barriers decreased significantly over time, with no difference between the groups. Significant decreases in body weight were correlated with improvements in physical activity and weight loss eating behaviors (p<.05), but not with decreases in energy intake. Conclusions. The intervention resulted in significant weight loss and improvements in physical activity and eating behaviors. However, the addition of resistance exercise or mindfulness training did not improve these short-term outcomes. It remains important that alternative behavioral approaches be examined over a longer duration to improve weight-related outcomes in overweight adults.