To assess the relationship between the self-perceived consultation time and the knowledge of the proposed treatment. Secondary data from a 2015 national survey of health services in Peru were analyzed. The self-perceived consultation time was calculated by asking how long it took from when you entered the consultation until you departed. It was then categorized as low, medium, and high. Five self-reported questions were used to construct a knowledge of the prescribed treatment. Adjusted regression models from the Poisson family models were used to evaluate the relationship. We report adjusted prevalence ratios (aPR) with their 95% confidence intervals (95%CI). A total of 9939 outpatients were analyzed, with 58% women; the average age was 44 years; and 45.4% had higher education. Using low self-perceived consultation time as references, medium and high consultation times were associated with understanding the prescribed treatment (aPR=1.17; 95%CI, 1.04–1.33 and aPR=1.30; 95%CI, 1.20–1.40, respectively). Patients who reported a medium and high self-perceived consultation time better understood the prescribed treatment. Healthcare professionals should strive to maximize consultation time to ensure effective communication and improve patient knowledge of treatments, improving overall patient satisfaction and health outcomes. •71.3% of the participants perceived consultation time as between 10 and 15 min.•Seven out of 10 respondents understood the prescribed treatment.•Consultation time was associated with understanding of prescribed treatment.•This association was increased to a consultation time of 15 min.