This study aimed to determine whether self-assessed puberty is sufficiently reliable and valid to substitute for physician examination when feasibility of physician examination is low (e.g., behavioral research). Adolescents (convenience sample N = 178 endocrinology patients and N = 125 from educational trial; mean age 12.7 and 11.3 years, respectively) participated. Self-assessments were validated against physician Tanner ratings and by associations with bone density, gender, and age. Highest exact agreement between physicians and adolescents was 54% for females' and 55% for males' ratings of pubic hair. More than 85% agreement within one stage was obtained for most measures. Significant associations were found for age and bone between adolescents in earlier and later stages of development and for developmental stage between genders for each age group. Results suggest predictive and discriminate validity of self-assessments. Self-assessments may be useful when estimates of pubertal development are sufficient and for studies barred from physician examination.