Objective: Competency-based curricula aim to equip students with sufficient skills to enable them to deliver dental care safely. Assessment represents an essential component of a successful competency-based educational experience. This study investigated faculty and self-assessment of impressions, the cornerstones for any prosthodontic treatment, made by dental students in their first clinical prosthodontic course. Methods: 237 “first-attempt" preliminary impressions (115 maxillary; 122 mandibular) were assessed by 2 calibrated professional faculty and self-assessed by the students themselves. Assessment was based on specific clearly-defined criteria and a 3-level rating rubric: 0(non-acceptable); 1(acceptable); 2(ideal). Faculty assessed the impressions independently then together to agree on its acceptability. Impressions were counted acceptable when at-least 1 was scored for all criteria and students were considered competent in this clinical skill. Comparison between faculty scores and between faculty and self-assessment scores were statistically analyzed (P< 0.05). Results: Based on faculty assessment, out of the 237 impressions; 2.5% (4 maxillary; 2 mandibular) were ideal, 62.45% (80 maxillary; 68 mandibular) were acceptable and 35% (31 maxillary; 52 mandibular) were unacceptable. Tray selection and border thickness were the most identified defective criteria. Inter-assessor agreement exceeded 95% in most criteria. There were statistically significant differences between faculty and student self-assessment scores with the latter giving higher scores. Conclusions: Students, in their first clinical course, usually require more than one attempt to make acceptable impressions. Competency was higher for maxillary impressions. Clearly-defined criteria and rubric-based assessment resulted in satisfactory agreement levels between assessors. Undergraduate students, at this educational level, tend to over-rate their work.