Objective: The microorganisms can survive on different surfaces which thus becomes a potential reservoir of infection. The aim of this study was to determine the level and type of microbial contamination on mobile phones from medical students in the Faculty of Medicine and laboratory staff in the Clinical Hospital Centre in Rijeka. Furthermore, the goal was to determine whether there are differences in the microbial contamination of mobile phones between these two groups, the differences based on sex subjects and types of mobile phone keypad. Patients and Methods: The study included a total of 154 participants, 83 medical students and 71 laboratory worker. Surface sapling of their mobile phones was conducted by contact application with CT3P agar and after an incubation of 24 hours at 35 ± 2 ° C the total number of bacteria per cm2 (CFU / cm2) were determined. The bacteria were futher identified based on the macroscopic and microscopic appearance, and various biochemical tests. Results: The total number of bacteria was significantly higher in the group of students and males of both groups. On mobile phones in both groups of participants, Staphylococcus epidermidis and other coagullase negative staphylococci. In addition, the presence of Staphylococcus aureus and pathogens belonging to the genus Enterococcus was found, whil Proteus genotype was found only in a group of laboratory workers. There were no significant differences in microbial contamination of mobile phones with a keyboard than in those with touchscreen. Conclusion: The level and type of microbial contamination on mobile phones can be a potential source of infection. As isolates of bacteria, Staphylococcus aureus, enterococci and enterobacteria are well known cause of hospital infections, further tests within the hospital environment, in order to confirm the validity of the introduction of guidelines for the implementation and control of hygiene of mobile phone in health care facilities are preferred.