In this study the health habits performed by nursing students during their practices in hospitals are describe in the province of Cádiz, Spain and the relationship between these activities involving risk, and the level of knowledge of Public Health of these students. A total of 397 nursing students were studied, 43% male, with an average age of 21.6 years (SD 2.9); the average practice period per student was 73 days. Washing of hands before and after each intervention is performed by 97% of students, and gloves are used on all the sanitary occasions recommended by only 21%; the groups using masks least are those not vaccinated for influenza and not subjected to a Mantoux test (p < 0.05). The relationship between taking unnecessary risk in hospital practice and the low level of knowledge is positive (collective protection p < 0.05, use of gloves p < 0.05, among others).