BackgroundDental education has placed continued emphasis on self-regulated learning (SRL) and its subprocess, self-assessment. This study set out to evaluate the effectiveness of a novel workplace assessment method in developing trainees’ self-assessment of operative procedures.MethodsA Direct Observation of Procedural Skills (DOPS) form was modified for the use and measurement of self-assessment. Participants were trained on how to conduct self-assessment using the designed assessment form and its grading rubric. Feedback and feedforward sessions were given to address self-assessment and performance issues. AP-valueless than 0.10 was considered significant and the confidence level was set at 90%.ResultsThirty-two Year 5 dental students with an age mean of 22.45 (SD = 0.8) completed five self DOPS encounters during the clinical operative dentistry module in 2022. The aggregated total deviation (absolute difference) between self-assessment and teacher assessment decreased consistently in the five assessment encounters with a significant mean difference and a medium effect size (P= 0.064, partial Eta squared = 0.069). Participants’ self-assessment accuracy differed from one skill to another and their ability to identify areas of improvement as perceived by teachers improved significantly (P= 0.011, partial Eta squared = 0.099). Participants’ attitudes towards the assessment method were positive.ConclusionsThe findings suggest that the self DOPS method was effective in developing participants’ ability to self-assess. Future research should explore the effectiveness of this assessment method in a wider range of clinical procedures.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12909-023-04474-z.