The origins of Santo Tomás Hospital date back to 1703, when King Philip V of Bourbon gave the name of Santo Tomás de Villanueva Hospital to the hospice founded a year earlier by the Bishop of Panama, Friar Juan Argüelles, to care for poor women at the site we now call Santa Ana. It was given this name because the hospice opened its doors on September 22, the feast day of Saint Thomas of Villanueva.

In 1819, construction began on a new building for Santo Tomás Hospital on Avenue B.

During this period (the first half of the 19th century), hospitals were staffed primarily by religious orders. Therefore, when the Colombian government persecuted them, Santo Tomás Hospital was significantly affected. However, in 1864, 1867, 1868, and 1878, the Legislative Assemblies of the Sovereign State of Panama allocated sums of money for the repair of the hospital building and the construction of new wards.

Beginning in 1886, Monsignor Fermín Jované, president of the Board of Directors of Santo Tomás Hospital, acquired a plot of land for the expansion of the hospital, thus initiating a phase of improvement in its facilities.

Political conflicts led to the outbreak of the so-called Thousand Days' War (1899-1902), which affected Panama, a department of Colombia. During this armed conflict, Santo Tomás Hospital served as a primary care hospital; consequently, by the time of Panama's separation from Colombia, the hospital was in a deplorable state.

HST offers a comprehensive range of adult medical and surgical specialties, including:

• Internal Medicine

• General Surgery

• Cardiology

• Endocrinology

• Neurology

• Obstetrics and Gynecology (including a maternity ward)

• Orthopedic Surgery

• Psychiatry

• Radiology

• Infectious Diseases

• Emergency Medicine
  The hospital serves patients aged 15 years and older and refers pediatric and oncology cases to specialized institutions

As the flagship public hospital, HST is recognized for its role in medical education and training generations of Panamanian and international doctors. It is a vital safety-net facility for those without private or social security insurance, serving 40–60% of Panama’s population who rely on the Ministry of Health for care. The hospital is known for its commitment to accessible, high-quality healthcare and continuous adaptation to meet the country’s needs.