The researchers said the technique displayed by the chimpanzees provides "further support for their exceptionally large and flexible cognitive tool kits".
While chimpanzees are known to hunt other animals, this is believed to be the first time they have been observed preying on tortoises.
The researchers, from the University of Osnabruck and Max Planck Institute for Evolutionary Anthropology in Germany, observed 10 animals hunting hinge-back tortoises, which are native to Africa, on 38 occasions, 34 of which were successful.
The chimpanzees hunting tortoises were mainly male and used a "distinct smashing technique".
The tortoise meat was shared with other chimpanzees, including those who had been unsuccessful in opening the shell, a total of 23 times.
"In the two cases where adolescent chimpanzees attempted to smash open a tortoise, they were unsuccessful," the authors wrote.
"Similar to nut cracking in chimpanzees - a percussive technology which is only mastered at the age of approximately nine to 10 years - the acquisition of a successful tortoise smashing technique may rely on a certain amount of strength.
"In addition, it may also involve a relatively long period of time to learn, practise and refine."
Similar smashing techniques have been observed in the species to get into nuts and hard-shelled fruits.