Childhood sexual abuse increases risk for adult obesity. A potential contributing factor is altered cortisol secretion. In this pilot study, relationships among childhood sexual abuse, diurnal salivary cortisol secretion, and weight loss were explored in 17 bariatric surgery patients. Measurement points were before surgery (baseline) and 3 and 6 months after surgery. Childhood sexual abuse was measured by the Childhood Trauma Questionnaire. The results showed moderate but nonsignificant positive correlations between the childhood sexual abuse subscale score and baseline morning cortisol, evening cortisol, and daily mean cortisol. An unexpected positive correlation was noted between the Childhood Trauma Questionnaire total score and weight loss at six months. Diurnal cortisol secretion did not change over time after surgery nor correlate significantly with weight loss at six months.