Introduction: The characteristics of new medical students are important to estimate the relevance of the courses they will attend during their professional training. Objective: Determine the profile of students and the impact of undergraduate courses on medical students from Norbert Wiener University in Lima, Peru. Methods: A prospective study was conducted of 148 second-and third-year undergraduate students during the year 2019. These students had already attended basic, specific and specialty courses. A total 34 courses were selected for impact evaluation, using a questionnaire containing 53 multiple choice closed-ended questions divided into three sections: 1) demographic data, 2) frequent activities and 3) course impact. Results: Seventy-seven (55.8%) students were aged 20-30 years, 69.6% were female and 26.8% were workers. The students spend a fair amount of time reading scientific articles (61%) and little time learning languages (69.3%) or about sports, art and politics (≥ 72%). The highest-impact specific courses were Normal Morphophysiology I (74%) and II (71.5%), Damage and Responses I (72.1%) and Nutrition for Health Sciences (44%), whereas the specialty courses obtaining the highest percentages were Semiology, Physiopathology and Clinical Reasoning (72.4%), Internal Medicine I (73.5%), Damage and Responses II (65%) and Internal Medicine II (76.5%). Conclusions: Determination was made of a heterogeneous profile and a high impact of specific and specialty undergraduate courses in Peruvian medical students.