Objective. To identify temperament and behavioral patterns in children with difficult toilet training and to compare those children with same-aged toilet-trained children. Methods. We compared 46 referred clinic patients who were difficult toilet trainers (DTT) with 62 comparison children (CC) using the Carey-McDevitt Behavioral Style Questionnaire, the Parenting Scale, and a questionnaire of toilet-training history. Results. CC were more likely to have easy temperaments (odds ratio [OR]: 33.51). DTT were more likely to be less adaptable (OR: 3.12), more negative in mood (OR: 2.79), less persistent (OR: 2.97), and lower in approach (OR: 1.85). DTT were more likely than CC to be constipated (OR: 3.52), although 55% of CC were constipated. DTT were likely to hide to stool (74%) and to ask for pull-ups in which to leave stool (37%). Parenting styles did not differ between the groups. Conclusions. Although the referral population may be inherently biased, these data suggest that difficult toilet training is associated with difficult temperamental traits and constipation in affected children.