Objective: The sense of joint position, which is one of the sub-parameters of proprioception, plays a very important role in initiating and stimulating voluntary and involuntary movements. The ImageJ software program is a free computer program used to make certain measurements on the material photographed in basic medical science laboratories. Angular measurements are also made in the program. In this study, we aimed to use the angular measurement tool to evaluate the sense of joint position in stroke individuals. For this purpose it is investigated the intraexaminer and interexaminer reliability, criterion-related and construct validity of this program in stroke patients. Material and methods: 50 stroke patients and 51 healthy control groups were included in the study. All stroke patients were assessed in four sessions, with three day intervals. Two fixed physiotherapists performed measurements at different times for the ImageJ software program. The isokinetic measurements were performed on all stroke patients session one. ImageJ software program measurements were carried out once on healthy people with three trials in a session. Results: The ImageJ software program showed good intraexaminer and interexaminer reliability. In measurements on the stroke patients significant correlations were observed between isokinetic equipment and ImageJ software program for the right and left knee (r=0.77, r=0.77, p