This study was conducted to determine if microbial infection was a significant factor in patients with undiagnosed craniofacial pain. Of the 150 patients from whom intra-bony cultures were obtained, 23 different groups of isolates were obtained. There were 49 (32.67%) patients whose cultures exhibited growth of microbes other than routine oral flora, mixed skin flora or routine respiratory flora. The most common was of the Streptococcus species (11 or 22.91%) of the 49. Sixty-seven (67) (44.67%) of the total cultures demonstrated the growth of mixed skin flora, nineteen (12.67%) demonstrated the growth of routine respiratory flora and sixteen (10.67%) demonstrated the growth of routine oral flora. No bacterial isolates were found in 16 (10.67%) cultures. The most common histological diagnoses of those who exhibited pathogenic microbial growth were, in order: 1. focal osteoporotic marrow defect; 2. ischemic osteonecrosis; and 3. chronic nonsuppurative osteomyelitis.