•Exposure biomarkers were measured in urine collected during pregnancy and boyhood.•Some prenatal exposures were associated with reduced odds of adrenarche and puberty.•Prenatal exposures were not associated with boyhood hormone levels.•Boyhood exposures were not associated with adrenarche or puberty.•Some boyhood exposures were associated with decreased testosterone levels. Phthalates and BPA are known endocrine disruptors and exposure in pregnant mothers and children is ubiquitous. We explored the relationship of prenatal and childhood exposures with pubertal onset and sex hormones in boys (ages 8–14). Phthalate metabolites and BPA were measured in maternal 3rd trimester or childhood urine. Sex hormones DHEAS, estradiol, inhibin B, SHBG, and total testosterone were measured in serum. Adrenarche and puberty were assessed by pediatrician. Prenatal exposure to some phthalates was associated with decreased DHEAS and inhibin B levels, and with increased SHBG. Prenatal exposure to most phthalates and BPA was associated with greatly reduced odds of adrenarche (odds ratios OR=0.12–0.65) and slightly reduced odds of puberty (OR=0.50–0.98). Childhood exposure was not associated with adrenarche or puberty, but some phthalates and BPA were associated with increased SHBG levels and decreased total and free testosterone levels.