Background <p>Sleep is an important component of human biological functioning and is necessary for optimal health and the maintenance of cognitive and psychological functions. Sleep hygiene is a collective term for the behaviors and environmental factors associated with good sleep.</p> Objectives <p>To assess the prevalence of poor sleep hygiene practices and poor sleep quality among medical students and to test the hypothesis that poor sleep hygiene is correlated with poor sleep quality.</p> Methods <p>This cross-sectional study was conducted among 504 medical students at Tanta University, Egypt, using a random two-stage cluster sampling technique. Two validated questionnaires were used, the Pittsburgh Sleep Quality Index (PSQI) and the Sleep Hygiene Index (SHI), in addition to a sociodemographic section.</p> Results <p>The prevalence of poor sleep quality among the study participants was 71.2%. A total of 93.6% of the participants reported having poor sleep hygiene. There was a statistically significant positive correlation between sleep hygiene practices and sleep quality (<i>r</i> = 0.366, <i>p</i> &lt; 0.001). The prevalence of poor sleep quality was the highest among students in the first grade (83.6%) and decreased to 66.0% among students in the fifth grade (<i>p</i> = 0.012). Using the bed for activities other than sleeping or sex; thinking, planning, or worrying when in bed; and doing important work before bedtime were the three most prevalent negative sleep hygiene practices, affecting 59.3%, 58.9%, and 54% of the participants, respectively.</p> Conclusion <p>Poor sleep hygiene practices and poor sleep quality are highly prevalent among Egyptian medical students. Medical students in their early academic years had a greater prevalence of poor sleep quality. Future educational programs on sleep hygiene are needed to raise awareness and possibly improve overall sleep quality in this population.</p>