Having a good sleep quality is essential for a healthy life. Lack or poor quality of sleep can negatively affect various brain functions such as emotional processing and memory acquisition and consolidation. In addition, prolonged sleep deprivation, as well as the deterioration of the sleep quality are correlated with depressed mood, anger, aggressive behavior and anxiety. The prison experience can be inherently stressful and lead to disturbed sleep patterns. In prison, the most common sleep disorder is insomnia. When left untreated, it can negatively affect daytime functioning and work productivity, and it can influence inmate adverse behavior such as exacerbating irritability or aggression. Improving sleep in prison offers the potential to positively impact several of these common risk factors for both staff and inmates. Thus, we propose a sleep hygiene treatment to improve sleep habits in the prison environment. Here, we will discuss preliminary data of the impact of one-month treatment of sleep hygiene in prison inmates on sleep quality, cognitive functions and emotional variables.