Mumps is a world-wide distributed human infectious disease. The causative agent is mumpsvirus, a single-stranded RNA virus belonging to the Paramyxoviridae. Mumpsvirus causes a variety of illnesses, which depend in part on humans' age and sex. Parotitis and meningitis as well as respiratory tract infection in children and orchitis in pubertal and postpubertal males are very common. Asymptomatic infections have also been frequently described. The treatment for mumps infection is symptomatic, there is no specific antiviral therapy. Immune prophylaxis with an attenuated life vaccine is the most important strategy of mumps prevention. During the last years, an increased number of mumps cases have been observed in several countries with a general recommendation for mumps vaccination. Young adults have been most frequently affected. The lack of immunity in this population is likely to be responsible for the increasing number of mumps cases.