The prevalence of drug resistance among clinically significant blood isolates of Staphylococcus epidermidis (n = 464) and consumption of antibiotics at a tertiary care teaching hospital (Meilahti Hospital, Helsinki) were analysed for the period 1983-1994. Resistance to methicillin increased from 28 to 77%. Simultaneously, usage of third-generation cephalosporins increased nearly sevenfold (from 8.6 kg/ to 56.4 kg/year). A significant correlation was found between percentages of methicillin resistance and usage of penicillinase-stable beta-lactam agents, including cloxacillin, imipenem, and first-, second-, and third-generation cephalosporins (r = 0.737, p