The current study had two purposes. The first purpose was to examine the association between family rules and routines and first grade children's teacher-rated and peer-rated behavioral competencies (e.g., emotional symptoms, conduct problems, peer problems, hyperactivity, and prosocial behavior) after controlling for both family stressors (i.e., single parent home, mobility, socioeconomic status, property ownership) and child ethnicity (African American, Caucasian, Hispanic). The second purpose was to determine if child regulatory control abilities mediates the effects of family rules and routines and children's behavioral competencies. The parents of 215 ethnically diverse children (38%, Caucasian, 22% African American, 33% Hispanic, 7% Other) were interviewed in their homes with a modified and shortened version of Family Routines Inventory (FRI; Jensen, James, Boyce, & Hartnett, 1983). Teachers completed the Strengths and Difficulties Questionnaire (SDQ; Goodman, 1997), and peers completed a modified version of the Class Play (Masten, Morison & Pelligrini, 1985). Scores from the SDQ were standardized and combined with the standardized scores obtained from the peer nominations to create composites of the behavioral competencies. Additionally, teachers completed a modified version of the California Child Q-set (CCQ) (Block & Block, 1980) as a measure of these children's regulatory control abilities. African American parents' ratings of their family's rules and routines were higher than those of Hispanic and Caucasian parents' ratings. Additionally, family stressors were positively associated with higher teacher and peer ratings of conduct problems and lower ratings of prosocial behavior. Neither ethnicity nor family rules and routines predicted child competencies. A statistically significant curvilinear relationship was found between family rules and routines and conduct problems such that children of parents reporting the highest and lowest levels of family rules and routines have more conduct problems. No associations were found between family rules and routines and child competencies or children's regulatory control abilities. Limitations of the study are discussed in terms of inadequate measurement of family rules and routines, a defensive response set, self-selection on the part of the parents to participate in the interview, and a sample that is not representative of the community of parents and children in the participating schools.