Objective: To determine the perception of patients regarding physicians communication skills at the outpatient clinic of a teaching hospital in Lima-Peru, using the Communication Assessment Tool (CAT). Methods: The study population was the group of patients treated in the outpatient clinics of the Cayetano Heredia Hospital. The CAT questionnaire contains 15 questions, and a version validated for Spanish was used. The perception of communication skills was defined as the sum of the scores of all the items, over the number of items, defined as: poor (1), fair (2), good (3), very good, (4), and excellent (5). Results: The percentage of patients who rated communication skills as "poor" (average CAT Score) was 6.8%, "fair" 27.2%, "good" 23.9%, "very good" 30.1 and "excellent" 12.1%. Statistically significant differences were found when comparing the age ranges and among the different levels of education. The group of patients between 18 and 29 years old gave higher scores in the instrument (range 2.2 to 4.87, p = 0.001). Furthermore, when the educational level of the respondent was high, the participants tended to rate physicians with higher scores (range 3.67 to 4.73, p = 0.001). Conclusion: We found that 66.2% of patients had a positive perception of the physicians communication skills; only 12.1% rated it as "excellent," a value well below what is reported in the literature. Those who gave the best rating were younger patients with the highest level of education.