A retrospective study of 96 Campylobacter jejuni isolated from farm animals and the environment showed that most were less susceptible than the NCTC type strain to nalidixic acid (MICs 4–32 mg/L), ciprofloxacin (MICs 1–2 mg/L) and erythromycin (MICs 16–64 mg/L), but had similar susceptibility to tetracycline (MICs 4–8 mg/L) and kanamycin (MICs 4–8 mg/L). None had the high MICs of ciprofloxacin (>32 mg/L) or erythromycin (1024 mg/L) typically associated with clinical resistance in this species. Some farms used antimicrobial agents, but there was no obvious association between the use of agents and the susceptibility of the isolates.