Homicide is recognized as a global public health problem. Finland has the highest overall homicide rate of the Nordic countries in comparisons over short time periods. Using the 39-year time series of homicide incidents in Finland from 1957-95, we analyzed the trend in homicide rate. In addition, we explored for the first time over the time trend in the seasonal variation of homicide and compared seasonal statistics over eight successive time periods. The present study revealed that there has been steadily increasing trend in homicides in Finland since 1950s. At the same time, the seasonality of homicide has decreased markedly. The peaks in homicide rates occurred commonly during summer and the troughs during winter.