Behavioral weight loss interventions are the standard approach to weight loss for overweight adults; however, adherence to the components of these programs is a challenge and an area of extensive interest in the field of obesity prevention and treatment. Purpose. This study examined whether perceived importance of and willingness to engage in weight loss behaviors predicted weight loss in overweight, previously sedentary adult men and women. In addition, these variables were examined in relation to actual engagement in weight loss behaviors, namely self-monitoring and attendance. Methods. Data from 30 overweight (body mass index (BMI) = 32.4 ± 2.7 kg/m²) men and women (age = 42.5 ± 8.1 years) who participated in a standard behavioral weight loss intervention that included behavioral modification strategies, moderate caloric restriction, and progressive exercise prescriptions. Body weight, perceived importance, and willingness were assessed at 0 and 12 weeks. Results. The intervention resulted in a decrease in body weight, body mass index, caloric intake, and fat intake (p < 0.05) and an increase in energy expenditure (kcal/week) (p < 0.05). Individuals reported lower total perceived importance and willingness scores at week 12 (p < 0.05). Perceived importance and willingness for self-monitoring, eating, and exercise behaviors were correlated at both baseline and week 12. However, neither perceived importance of or willingness to engage in self-monitoring and eating behaviors at baseline were found to be predictive of weight loss. Willingness to self-monitor at week 12 was positively correlated with weight loss (r = 0.40, p = 0.03). In addition, negative correlations were found for perceived importance of exercise behaviors at week 12 and weight loss and willingness to engage in exercise behaviors at baseline and weight loss. Conclusion. The present study provides preliminary support for the relationship between perceived importance of and willingness to engage in weight loss behaviors; however, the ability of these two variables to predict weight loss is unclear. Further understanding of perceived importance of and willingness to engage in behavioral weight loss strategies among adults participating in weight reduction programs may allow for personalized interventions and more successful weight losses.