Introduction: The cosmetologists' health complications can be inducted by their work conductors. The presence of numerous biological harmful factors in their future workplace requires from graduates the faculty of cosmetology extensive knowledge about health threats and prevention methods. Purpose: The survey aimed to get to know and compare the knowledge of students of the first and third year of Cosmetology at the Lomza State University of Applied Sciences on the biological hazards present in cosmetologist's work. Materials and methods: 50 female students (24 first-year students and 26 third-year students) took part in the survey. Results: In almost all cases, responses from third- year Cosmetology showed a higher level of knowledge of biological infections which may threaten in the beauty parlor for themselves and their clients. Also, in the area of preventing the spread of these infections, they had a higher knowledge than their younger friends. Conclusions: The level of knowledge of third-year students is significantly higher than the knowledge of first-year students in Lomza State University of Applied Sciences. It is satisfactory that first-year students who already started education in this field, they know biological threats.