To study N. gonorrhoeae resistance in Spain. We evaluate 402 strains consecutively isolated in 7 Spanish cities (Barcelona, Bilbao, Madrid, Murcia, Seville, Valencia and Valladolid). The MIC to 9 antimicrobial agents was determined by agar-dilution (DST) method. We found a high incidence (15.7%) of penicillinase producer strains (NGPP). Most (53.3%) of all non-NGPP strains showed reduced sensitivity to penicillin and 1.5% of the strains had chromosomally mediated resistance. All NGPP strains and 90% of non-NGPP strains showed reduced sensitivity to tetracycline (MIC greater than 0.23 mg/l). We did not found any strain with high-level tetracycline resistance. MIC90 for the other drugs tested were: erythromycin, 0.125 mg/l; spectinomycin, 16 mg/l; cefoxitin, 2 mg/l; cefuroxime 0.06 mg/l; ceftriaxone 0.0037 mg/l; ofloxacin 0.06 mg/l and ciprofloxacin, 0.0018 mg/l. NGPP are very prevalent in Spain. Most of these strains had chromosomally mediated resistance to penicillin and tetracycline. We did not found resistance to other antimicrobial agents.