Biochemical profiles were studied in 102 Campylobacter isolates from patients affected by enteric disease in Orense (Spain) over a 1-year period. The isolates were identified as hippurate-positive Campylobacter jejuni (n = 90), Campylobacter coli (n = 10) and hippurate-negative C. jejuni (n = 2). Seventy-seven of the hippurate-positive and both hippurate-negative C. jejuni isolates were biotyped as C. jejuni subsp. jejuni biotype 1, nine as C. jejuni subsp. jejuni biotype 2 and four as C. jejuni subsp. doylei. Hippurate-hydrolysis was correlated to a simple scheme based on L-arginine arylamidase production, propionate assimilation and malate assimilation which yielded sensitivity and specificity values of 0.90 and 1.00, respectively. Effective grouping of nalidixic acid-resistant C. jejuni and C. coli isolates (38.5% of the total) was also achieved.