Investigations of contributors to and consequences of the parent-child relationship require accurate assessment of the nature and quality of parenting. The present study describes the development and psychometric evaluation of the Laboratory Parenting Assessment Battery (Lab-PAB), an observational rating system that assesses parenting behaviors during the early childhood years. Dyadic parent-child interaction was assessed observationally in a community sample of 154 families (154 mothers, 154 fathers, 154 biological children 3-6 years old). Parenting behaviors were rated with a comprehensive coding system that assessed a broad range of relevant constructs drawn from the literatures on parenting, attachment, affect, and interpersonal relationships. A series of psychometrically informed data reduction strategies ultimately yielded 5 parenting scales (Involvement, Positivity, Hostility, Intrusiveness, Discipline). Scores on the Lab-PAB parenting scales demonstrated adequate internal consistency and interrater reliability in our sample, as well as convergence with measures of related constructs. The use of this standardized observational measure has the potential to further future longitudinal investigations of the effects of parent-, child-, and family-level factors on the quality of parenting, and of parenting on child outcomes. (Contains 5 tables and 4 footnotes.)