Objectives: To determine the prevalence of sleep-disordered breathing in Peruvian truck drivers working at high altitudes and to validate the automatic versus manual scoring system of a respiratory polygraph test. Methods: A cross-sectional and probabilistic study was conducted on truck drivers working the day shift at 2,020 meters above sea level. The collected information included anthropometric variables, the Epworth Sleepiness Scale (ESS), and the Lake Louise Acute Mountain Sickness (AMS) Questionnaire. A simplified type III screening instrument was used, and each recording was scored both automatically and manually. Results: In a total population of 70 drivers, 63 respiratory polygraph tests were conducted and four recordings were excluded. Out of the final sample of 59 (84%) drivers, 46 (78%) were normal, seven (12%) had altitude-induced central sleep apnea, and six (10%) showed obstructive sleep apnea-hypopnea syndrome. The results from the ESS and the Lake Louise AMS Questionnaire were normal for all three groups. Six out of seven drivers with central sleep apnea were intermittently exposed to altitude. No demographic variable was able to predict the abnormal test results. The automatic and manual methods for scoring respiratory events were similar according to the Pearson correlation and the Bland-Altman analysis; r = 0.992 for the apnea-hypopnea index (p < 0.001) and r = 0.945 for the central sleep apnea index (p < 0.001). Conclusion: A high prevalence of sleep-disordered breathing was observed, and no predictive variables for an abnormal study were identifed. The use of simplified instruments is recommended to identify sleep-disordered breathing in drivers working at high altitudes who are far away from specialized sleep laboratories.