The men - aged 49 and 36 - were detained after a two-month long police investigation in the capital Montevideo.
The police suspect that the hospital workers brought in poison from Brazil and gave it to the patients who were in a critical condition.
The alleged killings took place in the cardiology unit of the Maciel Hospital and in the intensive care unit of the Spanish Mutual Care.
Judge Rolando Vomero, who is overseeing the case, told the newspaper El Observador that other hospital staff and relatives of alleged victims reported what could be dozens of cases. Read more