The trio, from northern Poland, were charged over the death of the 18-month-old animal after an investigation which began in October, prosecutor Jan Wierzbicki told PAP.
The probe began after rangers in the Tatra Mountains national park found the bear dead in a stream.
Rangers later told AFP that the tourists had owned up to stoning and drowning the 46-kilogramme (102-pound) bear, but that they claimed to have acted in self-defence after it attacked them.
However, rangers said such a young animal is no real threat to humans and that it must have been provoked.
Rangers found bread at the scene, suggesting that the tourists had fed the bear with their picnic sandwiches, which is illegal.
The rangers were alerted after two of the tourists went to a hospital in the resort town of Zakopane to have treatment for the injuries purportedly caused by the animal.
Doctors, however, noted nothing but scratches and no sign of wounds that could have been caused by bear claws and so decided to call in the park authorities.
An autopsy on the bear revealed injuries caused by stone-throwing, but drowning was the cause of death, experts said.
The hikers could face between three months and five years in prison if found guilty of killing the animal.
Dozens of brown bears – a threatened species in Europe – roam the Tatras, which straddle Poland and Slovakia and are part of the Carpathian range.