Rationale, aims and objectives: A considerable amount of primary health care (PHC) clients comes in with medically unexplained complaints, leading to frequent consultations and high usage of services and health care costs. This study aimed to determine the prevalence of somatic symptom disorder among PHC attendees and to explore its relation with other mental disorders and risk factors. Methods: A cross sectional design was used to interview 400 attendees at five PHC centers in Nablus district, during Sept to Dec, 2019. Men and women age over 18 years old, without psychiatric diagnosis were invited to participate in the study. The Somatization scale of the Four-Dimensional Symptom Questionnaire was used to assess somatic symptom disorders. It is a valid tool to be used in PHC setting. Chi-squared test and multivariable logistic regression were used to explore determinant variables. Results: A high prevalence of somatic symptom disorder was seen in the sample [32.5% (95%CI= 27.9%-37.1%)]. The most prevalent symptoms were painful muscles (61.5%) followed by back pain (52.3%). Somatic symptom disorder was found to be associated with: Female gender [P =0.015 adjusted OR = 2.2 (95% CI= 1.3-4)], chronic diseases [P =0.027 adjusted OR = 2 (95%CI=1.1-3.6)], depression [P <0.001 adjusted OR = 3.2 (95%CI= 2.0-5.3)], and anxiety [P=0.032 adjusted OR = 3.0 (95%CI= 1.6-5.5)]. Additionally, attendees with high somatization were found to have significantly higher frequency of doctors visit [P=0.005 adjusted OR = 2.2 (95%CI= 1.3-4.0)] Conclusions: The prevalence of somatization among PHC attendees in Palestine is high. It is significantly higher among females, patients with chronic diseases, clients with anxiety and depressive disorders and patients with frequent doctors’ visits. Painful muscles and back pain are the most common symptom presented by patients, and this could be used initially by PHC physicians as a signal to consider for screening.