The study compared maternal and trained observer evaluations of infant temperamental characteristics, to determine how closely the ratings correspond, and to analyze the impact of maternal drug abuse habits on maternal ratings of infant temperament. In relating observer to maternal ratings of infant temperament, seven dimensions were compared: activity level, adaptability, approach, intensity, mood, distractibility, and persistence. Only two of these, activity level and persistence, showed significant correlations between observer and maternal ratings. A principal components analysis of the observer ratings revealed a constellation of characteristics--mood, approach, and adaptability-- which have been defined in the literature as characteristic of the "easy" baby. Maternal ratings of infants on these three dimensions appear to be negatively correlated with maternal drug habits; as maternal drug abuse scores increased, so did maternal reports of difficult infant characteristics. Includes eight references. (JDD)