Self-report measures of sexual maturation continue to be used to classify pubertal development even though their reliability remains in question. This study examined the accuracy of self-report measures by early adolescents in two settings. Standardized figure drawings depicting Tanner's sexual maturation scale (SMS) were shown to early adolescents at school (S1) and again in a clinical sitting (S2), and subjects were asked to rate their own pubertal development. Physical examination by a physician at S2 was used to corroborate sexual maturation. Participating in the study were 46 males, age 11-14 years (mean, 12.4, SD, 1.9), and 37 females, age 11-14 years (mean, 12.7, SD, 0.7). Concordance rate between physical examination and self-report of pubic hair development (males) at S1 was 58% (kappa = 0.35, p < 0.0001) and 78% (kappa = .66, p < 0.0001) at S2. Concordance rate of self-report of genital development at S1 and S2 was 27% (kappa = -0.06, p < 0.49) and 44% (kappa = 0.18, p < 0.04), respectively. Self-report of breast development demonstrated a concordance rate of 59% (kappa = 0.43, p < 0.0001) at S1 and 72% (kappa = 0.59, p < 0.0001) at S2. Concordance rate for self-report of pubic hair development in females was 58% at S1 (kappa = 0.42, p < 0.0001) and 75% at S2 (kappa = 0.64, p < 0.0001). There was a tendency for subjects to overestimate their development at early stages of maturation and underestimate development at later stages. Self-assessment of pubertal maturation can be utilized in research protocols when approximations of sexual maturation are desired, but it is of limited utility in establishing that puberty has been initiated or completed.