Patients with unexplained somatic symptoms are commonly seen in primary care. We assessed the explanatory models and common mental disorders in patients with unexplained somatic symptoms attending a primary care facility in a rural area of south India. One hundred consecutive patients diagnosed to have unexplained somatic symptoms attending a primary care facility were examined. The Tamil version of the Revised Clinical Interview Schedule was used to assess common mental disorders and the Tamil version of the Short Explanatory Model Interview was used to assess their explanatory models. Ninety-eight patients thought that their problem was serious. Sixty-nine, 41 and 40 claimed that it affected their work, family and social lives, respectively. Forty-two of the patients believed in black magic. Forty-four patients satisfied the ICD-10 PC criteria for common mental disorders. Depression was the commonest diagnosis (63.6%). Patients with psychiatric diagnoses admitted to emotional problems (chi2 = 46.9; p < 0.001), and felt that their problems affected their family (chi2 = 38.5; p < 0.001), social life (chi2 = 28.6; p < 0.001) and work (chi2 = 34.4; p < 0.001). More patients who satisfied criteria for psychiatric diagnosis felt that their problems were moderate or very serious (chi2 = 21.5; p < 0.001) and they feared they might become disabled or die (chi2 = 12.2; p < 0.001). Psychiatric syndromes were significantly associated with belief in black magic (chi2 = 7.01; p < 0.01). These associations remained statstically significant after adjusting for age, gender, literacy and socioeconomic indices using logistic regression. The majority of patients held strong beliefs regarding the physical nature of their complaints, believed In the serious nature of the problem and feared disability or death. There is a need to elicit specific explanatory models regarding the nature of illness in patients who present with somatic symptoms without organic causes. Understanding the patient's perspectives is a prerequisite for providing the necessary treatment and to dispel fears.