From 1970 to 1979, multiple myeloma was diagnosed in 184 residents of Northern Israel. The data were analyzed for variations by demographic factors, ethnicity, country of origin, and urban/rural residence areas. The average annual age-adjusted incidence rate per 100,000 residents was 1.78. The rates for males and females were 2.1 and 1.46/10(5) person-years, respectively. The male to female incidence ratio was 1.44:1.0. The average incidence rate was significantly higher for Jews than for Arabs and was higher for European Jews than for Afro-Asians or native Israelis. Urban areas had significantly higher rates than rural areas. A statistically significant increase in the incidence rates was demonstrated for the years 1975 to 1979 compared to the period 1970 to 1974. The increase was evident in all population categories, but was particularly prominent in females, the Jewish population, urban areas, and in the oldest age group. The results of the current study suggest that both culturally derived factors and industrial environment may play a role in the etiology of multiple myeloma.