To determine whether the findings of case-control studies of risk factors for child abuse may have been biased because of inattention to scientific principles of research design, 22-case-control studies were reviewed investigating either of two risk factors: (1) prematurity or low birth weight of the abused child or (2) young maternal age of the mother of the abused child. Each study was examined to determine compliance with seven methodologic standards that would minimize bias or distortion of the results. No study satisfied all seven standards. Two standards, choice of a specific control group and adjustment for differences in clinical and demographic susceptibility factors, most often affected the results. Studies complying with both of these standards indicated that prematurity or low birth weight is not a risk factor for abuse and that young maternal age at the birth of the abused child is likely to be a risk factor. Few studies complied with the standard concerned with avoidance of detection bias; this failure may have a major effect on the direction bias; this failure may have a major effect on the direction of the results of certain studies. Previous case-control studies of child abuse have important methodologic flaws that can affect the validity of the results. The standards presented should be helpful in planning methodologically rigorous studies.