At the Alma-Ata Conference in the late twentieth century, which addressed the development of primary health care systems worldwide, various models of PHC implementation were proposed. In Spain, building on the establishment of universal health coverage through the Social Security system, a model of primary care medicine was adopted. Although it has undergone modifications and faces multiple challenges today, it continues to operate as the backbone of the healthcare system. The Spanish primary care model is essentially universal, delivered through health centers staffed by multidisciplinary teams of physicians and nurses working under a fixed salary system. Care is provided without discrimination, and the primary care physician and nurse maintain a long-term relationship with patients, guiding them toward healthy, preventive lifestyles and referring them to specialized centers when necessary. This approach resolves more than half of all medical problems efficiently and effectively. Primary care medicine has evolved into a recognized medical specialty in its own right. At present, greater public investment is essential to ensure its optimal development and to meet the growing demands of modern healthcare systems.