The infection of autogenous vascular grafts from blood-borne contaminants is distinctly unusual. Two cases are reported in which a urinary tract infection caused by Pseudomonas aeruginosa occurred after autogenous saphenous vein bypass grafting. Despite appropriate intravenous antibiotic therapy for 10 days with clearing of both blood and urine, the patients subsequently had significant complications from graft infections. The factors thought to have contributed to this are discussed and the literature reviewed. Recommendations are made concerning the modification of the standard therapy in this situation.