The need for energy sources motivated Europeans to explore oil in Iran, which the most successful one began in 1901, under the D’Arcy Concession, followed by digging oil wells in the west and southwest of the country. Finally, oil was discovered in Masjed Soleyman (Masjid-i-Suleiman) in 1908, establishing the British-owned Anglo-Persian Oil Company (APOC), which later changed to the Anglo-Iranian Oil Company (AIOC). The D’Arcy Concession was canceled in 1933 and substituted by the 1933 Agreement, valid until Iran’s oil industry nationalization in 1951, when the National Iranian Oil Company (NIOC) was established, and which oversaw Iran’s oil industry from 1954 until the Islamic Revolution in 1979. The discovery of oil in 1908 rapidly shaped and facilitated the development of two major company towns, Masjed Soleyman (Masjid-i-Suleiman) and Abadan. These company towns were developed continuously and provided different amenities for their inhabitants, including European staff, Indian staff, and Iranian workers. In the meantime, healthcare facilities were one of the primary services provided by the oil companies. However, the approaches of oil companies varied in different periods. This qualitative study takes a historical-interpretive approach, uses primary and secondary sources to give an overview of the most essential healthcare-related efforts by oil companies. This study divided the companies’ efforts into three periods based on the oil contracts. Thus, the periods are from the D’Arcy Concession to the 1933 Agreement (1901–1933), from the 1933 Agreement to Iran’s oil industry nationalization (1933–1951), and from Iran’s oil industry nationalization to the Islamic Revolution (1951–1979). In the first period, APOC employed medical doctors, one of whom was Dr. Young, to treat their staff since they were exploring the oil. Dr. Young played a significant role in healthcare efforts and in resolving the conflict between the APOC and the locals. However, after discovering oil, APOC built a modern, equipped hospital in Masjed Soleyman (Masjid-i-Suleiman) and one in Abadan, prioritizing service to the staff and, later, the laborers. After the 1933 Agreement, due to new obligations, APOC (later AIOC) developed its existing hospitals in the major company towns and built new medical centers at a primary level in newly established company towns. Between 1951 and 1979, NIOC, due to its national aspects, developed existing hospitals and established new hospitals and clinics in the company towns, so each had its own equipped hospital. NIOC planned and built hospitals nationwide. In addition, nursing schools were established in oil-rich regions to train Iranians, and severe measures were taken to prevent and control infections and epidemics.