Measles vaccination is fairly beneficial. During the third year after launching of the vaccination programme, cumulative benefits accuring from vaccination outweigh the cumulative costs of vaccination. This conclusion is based on a study of the vaccination programme in Finland. According to the vaccination programme, all 1-year-old infants in Finland are vaccinated. The duration of the period under survey has been set at 25 years, the measuring unit is the Finnish mark and the price level is that of the year 1975. When comparing costs and benefits, these are converted to present day monetary values. Vaccination costs per vaccinated infant amount to 32 marks, and in total during the period 1975--1999 they will amount to about 34 million marks according to an interest rate of 9% and to about 41 million marks according to an interest rate of 6% in current monetary value. Benefits gained by vaccination, compared with costs, are manifold. The benefits of one vaccination have been estimated at 230 marks. In total, benefits during the period 1975--99 constitute ca 117 million marks at an interest rate of 9%, and ca 159 million marks at an interest rate of 6% in current monetary value, without any deduction for vaccination costs. The net gain of vaccination--with a deduction of vaccination costs--is ca 84 million marks at an interest rate of 9%, and ca 118 million marks at an interest rate of 6% in current monetary value.