Primary health care (PHC) aims to provide essential health care accessible to all at an affordable cost. It represents the first level of contact with the health system and addresses a majority of health problems through health promotion, disease prevention, treatment and referral services. The Alma-Ata Declaration of 1978 established PHC as a key WHO policy and the goal of "Health for All" by 2000. PHC focuses on maternal and child health, immunization, nutrition, sanitation and treatment of common diseases through primary health centers and community participation. While progress was slowed by various factors, PHC remains critical to developing sustainable health systems that equitably serve populations and address both communicable and non-communicable diseases.