A factor-analytical study was carried out with the Conners' Teacher Rating Scale (CTRS). It was applied to a total of 1746 special school students of both sexes in Hong Kong with ages ranging from 6 to 12. They included children with various handicaps, the majority being mental retardation, behavioural problems, and physical disabilities. The result indicated broad similarities to those factor structures obtained in other CTRS studies with normal or psychiatric populations. This established the applicability of CTRS to handicapped children of various types. Factors emerged in this study also bore close resemblance to those found in studies using other rating scales. Such convergence of findings suggested that these factors might represent useful dimensions in classifying problem behaviour in both normal and handicapped children.