OBJECTIVE To evaluate the reproducibility of the AO/Asif classification for humeral shaft fractures. METHODS Consecutive radiographs of the arm in both anteroposterior and lateral view from 60 patients with humeral shaft fractures were analyzed. Six observers who were familiar with the AO/Asif classification (three shoulder and elbow surgery specialists and three general orthopedists) were selected to make the analysis, which was done at three different times. The data were subjected to statistical analysis using the kappa coefficient. RESULTS The intra and interobserver concordance was statistically significant in all the analyses. CONCLUSIONS All the evaluators showed concordance between the three evaluations that was considered to be statistically significant. However, the highest values were found among the specialists.