Background: Protocol non-compliance in clinical research studies is common and can affect both patient safety and data integrity. There are no published studies which actively looked for non-compliance. The present study was carried out, against this background, with the objective of assessing the proportion of protocol non-compliance and evaluating those aspects of protocol where there was non-compliance. Methods: The study completion reports that were submitted to the institutional ethics committee for the period January 2017 to December 2017 were compared with the approved protocol. A checklist for recording protocol non-compliance was developed, which was validated by five experts and consisted of a 12-point checklist with responses such as yes, no, not applicable, and insufficient information. Results: Out of 193 studies, prospective observational studies were n = 120 (62.17 %), retrospective studies were n = 39 (20.21%), interventional studies n = 28 (14.51 %), and observational studies with both prospective and retrospective study design were n = 6 (3.11%). The study objective was modified in n=18 (9.32%) studies. Only n = 14 (7.24%) satisfied the selection criteria. Six studies (3.10%) did not collect the data as mentioned in the protocol. Fifty-eight studies (30.05%) did not achieve the calculated sample size, whereas n = 78 (40.41%) did not complete the study as per the stipulated study duration. Contrary to 180 protocol deviations found in this study, only 14 protocol deviations were reported by the principal investigator. Aspects like blinding and randomisation, which are relevant to interventional studies (n = 28), showed 100 % compliance. Conclusion: The research protocol is not adhered to in all aspects. Adequate training to investigators will help prevent non-compliance and enable us to conduct studies with higher ethical and scientific integrity. Keywords: study design, sample size, interventional studies, non-compliance