Background. Sleep habits and problems play a vital role in determining sleep quality. We describe sleep habits and problems among medical students and assess their possible effect on self-reported academic performance. Methods. We conducted a cross-sectional study among medical students at the University of Ghana during the 2014/2015 academic year. Data was collected using the Pittsburgh Sleep Quality Index (PSQI), a self-report questionnaire that assesses sleep quality over a 1-month time interval. Results. 153 medical students were recruited comprising 83 (54.2%) females and 70 (45.8%) males with a mean age of 23.1 ± 2.4 years. The mean duration of night sleep was 5.7 ± 1.2 hours; 88 (57.5%) students had sleep latency of 10-30 minutes while 18 (11.8%) woke up nightly. 23 (15%) students experienced nightmares, 13 (8.5%) snored at night, and only one student reported coffee intake of 2-3 times daily. Sleep quality was poor in 86 (56.2%) and was significantly associated with sleep latency, morning tiredness, daytime sleepiness during lectures, academic performance, living conditions, leisure time, frequency of nocturnal awakenings, waking up due to noise, sleep walking, and nocturnal awakening to use washroom. There was also a significant positive relation between sleep quality and academic performance (X2 = 10.004 p = 0.019). Conclusion. Poor sleep quality and daytime dysfunction are widespread among medical students in Ghana. There was a significant positive relation between sleep quality and self-reported academic performance.