This paper presents an experimental study of the heating value of medical waste using an input-output method. The study was carried out at the Oncological Hospital in Bydgoszcz, Poland, over a period of three months. The installation for thermal treatment consisted of a loading unit, a combustion chamber, and a discharge chamber (thermoreactor). The medical waste constituted the primary fuel, and high-methane natural gas acted as the secondary fuel. With regard to the high heating value and low humidity of medical waste, the thermal processing in the combustion chamber fulfilled the criterion of stable combustion (autothermal combustion). The average temperature in the combustion chamber was 665.5ºC during the testing period. The study showed that the heating value of the waste varied considerably. The amount of incinerated waste varied between ṁ_mw=70 kg/h and 140 kg/h during the testing period. The calorific value of the medical waste fluctuated between 8.5 MJ/kg and 41.2 MJ/kg, with a mean value of q_mw=19.1 MJ/kg.