The interrater reliability of a classification scheme of psychosocial stressors was assessed among 52 child psychiatrists in rating exercises with 28 case histories. Validity was evaluated in a field study of 377 cases rated by 39 of the same child psychiatrists. The impact of glossary descriptions on reliability and validity was also determined. Reliability was low with most Kappa values being in the range of 0.20 to 0.40. The glossary did not affect interrater reliability, but it significantly decreased the use of abnormal codes. The discriminant validity of the codes was supported in that the most commonly used codes were used with differential frequency in a pattern that conforms with the known psychosocial correlates of the different psychiatric conditions of childhood.