A multicenter case-control study was conducted in Italy in twelve areas covering a population of 7 million persons with the aim of verifying the hypothesis of an association between exposure to herbicides and to organic solvents and occurrence of lymphoma, leukaemia and multiple myeloma. 3420 cases were recruited in a three-year period (1991-1993), through periodical surveys in the main hospitals in each area. A random sample of the general population (2317 subjects) constitutes the control group. Cases and controls were face to face interviewed by trained personnel. A questionnaire was used asking about personal habits, residential and occupational history, past health status. Preliminary analyses, concerning a total of 1388 cases and 1718 controls, focused risks by occupation. Elevated risks of non Hodgkin's lymphoma (OR: 1.7; IC 95%: 0.92-3.02; based on 28 exposed cases), and of multiple myeloma (OR: 3.6; IC 95%: 1.51-8.63; based on 9 exposed cases) were shown for welders. Among female hairdressers there were elevated risks of non Hodgkin's lymphoma (OR: 1.8; IC 95%: 0.76-4.30; based on 8 exposed cases), multiple myeloma (OR: 3.3; IC 95%: 0.77-14.15; based on 3 exposed cases) and Hodgkin's disease (OR: 2.0; IC 95%: 0.93-4.47; based on 16 exposed cases).