B ackground: Polymerization is an important factor determining the success of composite resin restorations. Adequate composite resin polymerization knowledge will help dental professional students obtain good restoration results. Objective: To determine the level of knowledge of dental profession students in producing adequate polymerization of composite resin at Dental and Oral Hospital, Faculty of Dentistry, Trisakti University. Method: This type of descriptive observational study with a cross-sectional design was approved by the ethical test by the Research Ethics Commission of the Faculty of Dentistry, Trisakti University number 367/S1/KEPK/FKG/8/2020. The questionnaire was distributed to 30 respondents to be tested for validity (Pearson Correlation) and reliability (Cronbach's Alpha = 0,740) before being used as a research measure. Fourteen multiple choice questions on the questionnaire proved to be valid and reliable. Respondents filled out informed consent and questionnaires via google form application. The results of the answers to the questionnaire categorized the respondent's levels of knowledge into good, sufficient and insufficient. Results: A total of 100 respondents filled out a questionnaire which is proven valid and reliable. The results showed 23% of respondents had a good level of knowledge, 43% of respondents had a sufficient level of knowledge, and 34% of respondents had an insufficient of knowledge. Most of the respondents have a good knowledge of the type of Light Curing Unit (LCU), the application of the material, the resin composite irradiation procedure, and the effect of inadequate polymerization. Conclusion: Respondents have sufficient knowledge in producing adequate polymerization of composite resin. The question about the composition of the composite resin was not well answered by the respondents. In depth study of the factors that influence the polymerization of composite resins, especially the composition of materials is needed to support the basic theory and increase knowledge.