Daily variations in secrecy with mothers and fathers were examined in 108 poor, urban, diverse middle adolescents (M = 15.16 years, SD = 0.89). Adolescents completed online diaries over 14 days assessing secrecy from parents about school, personal, and multifaceted activities (e.g., staying out late), and bad behavior. Three-level hierarchical linear models indicated that there were significant daily fluctuations in adolescents' secrecy with mothers and that adolescents kept more secrets from mothers about personal than other activities. Secrecy with mothers also was associated with greater involvement in problem behavior. For both mothers and fathers, secrecy on the current day was associated with greater secrecy on the previous day and with poorer overall relationships (as aggregated across study days) with that parent. Thus, for mothers, secrecy appeared to be associated with both stable factors and daily variations, whereas for fathers, secrecy was associated primarily with stable factors. The results provide a detailed picture of secrecy in diverse adolescents' everyday lives. (Contains 3 tables.)