Early identification of children experiencing difficulties in learning is essential for timely and effective intervention. The aim of this study was to develop a screening instrument for identifying students with learning difficulties at the end of the first term of Primary 1 in Hong Kong. This paper describes the development and validation of a 27-item checklist on 594 students. Validity testing performed included content and expert, contrasted group, concurrent and predictive validity; all were found to be satisfactory. In addition, test-re-test reliability was assessed to be good. The checklist can be administered in 10 minutes for each student based on everyday observations of the student; no specific testing of the students would be required. A longer version with 97 items was also made available for teachers to conduct a more comprehensive evaluation of a child's performance. (Contains 1 figure and 3 tables.)