Objective: A drug use evaluation focusing on prescribed antibiotics among Greek indigent and Social Security patients. Method: Four hundred and forty-six indigent patients insured by Social Care and 332 patients insured under Social Security Funds were interviewed and their prescription records reviewed. Results: Although 88.5% of indigent patients stated that they had received instructions on antibiotic use and had understood these instructions, only 45.9% could correctly repeat these instructions. Only 9.9% read the enclosed leaflets and 59.4% reported asking the pharmacist for advice, 54.1% of these patients were unaware of the dosage of their medication, and the length of treatment was only written in 13% of cases. The most common diseases among indigent patients were respiratory infection (11.7%) and dental problems (10.1%). The latter ranked 11th among the insured patients (3.7%). Tuberculosis (3.3%) was still one of the most common diseases among the indigent patients. Overall, 30.9% of the prescribed daily defined dose (DDD) of medication for the indigent patients were for cardiovascular drugs (16.9% of the cost), 19.5% were for nervous system drugs (8.9% of the cost), 13.5% for gastrointestinal tract drugs (14.1% of the cost) and only 4.3% were antibiotics (but 16.9% of the cost). The most frequently prescribed antimicrobials were penicillins (45.6%), cephalosporins (19.7%), macrolides (12.6%) and quinolones (9.6%). Antituberculous agents made up 13.7% of the antibiotic prescriptions. The most widely prescribed antibiotics were amoxycillin + clavulanate (19.3%), amoxycillin (7.9%), cefaclor (5.6%), clarythromycin (5.1%) and rifampicin + isoniazid (6.3%). Conclusion: The present study emphasizes the need for more information on drug use among indigent patients and their information needs.