The article examines the strength and direction of relation between the size and ownership of hospitals in Poland and their efficiency. As the required data from the individual entities are unavailable, the authors use data aggregated at the level of voivodeships. Based on the results of Stochastic Frontier Analysis (SFA) they did not find any statistically significant relation between mentioned variables and hospital efficiency which would be robust to the change of the model specification. However, due to the data deficiencies, they also can not conclude, that such relation is nonexistent