A questionnaire survey of Belgian acute care hospitals was conducted to determine the methods used for detection of methicillin-resistant Staphylococcus aureus (MRSA), to estimate the prevalence of this organism during the period 1989-1991 and to describe the infection control measures used locally for limiting its spread. Questionnaires were returned by 144 acute care hospitals, with a coverage of 41 to 72 % of hospitals by province. Methods used for detection of MRSA included disk diffusion (91 %), microdilution panels (8 %) and oxacillin agar screen (9 %). Only 34 % of laboratories performed disk diffusion testing under optimal conditions for detection of heterogeneous resistance. Among 36 hospitals reporting complete susceptibility data of Staphylococcus aureus isolates tested during the study period (n = 24,153), a mean MRSA prevalence of 14 % was found (range: 0-70 %). The median prevalence increased from 9.5 % in 1989 to 13.7 % in 1991 and showed a significant linear increase during this period in 30 % of these hospitals (p < 0.01). Precautions used for controlling spread of MRSA included hand decontamination using either soap and water or antimicrobial preparations (68 % of hospitals), room decontamination (62 %), patient isolation (55 %) and various barrier precautions (24-49 %). Carrier screening was performed in 37 % of hospitals, but antibiotic decolonization was attempted in only 24 %. This survey identified areas for improvement in MRSA detection methods and underscored the need for multicentric surveillance of MRSA prevalence and a reappraisal of MRSA control strategies in Belgian hospitals.