Investigated the reliability and validity of a 34-item parent daily observation and reporting measure that allows for repeated assessments of child problem behaviors. Ss were 81 families with a 4-10 yr old target child. Normative data are presented, and influences on parental reporting (i.e., social desirability) are examined. Parent observation data were found to have substantial temporal stability and interparent reliability for the occurrence of previously targeted problem behaviors. A cluster analysis yielded 2 primary factors with good internal consistency (i.e., aggression and immaturity) and 2 secondary factors with moderate internal consistency (i.e., unsocialized and retaliation). Parents’ daily reports of targeted child problem behaviors correlated significantly with concurrent home observation data collected by independent observers.