We report a new method of studying brown bear (Ursus arctos) behavior. The method combines the technologies of Global Positioning Systems (GPS) and Global System for Mobile Communication (GSM). A GPS–GSM collar on a bear locates itself with the help of a GPS module, while the GSM module sends the location information to the researcher as SMS (short) message via a GSM mobile phone network. The collar is interactive and can receive SMS commands, for instance, to adjust the interval at which location information is transmitted. We tested the method in experiments in which people equipped with GPS–GSM mobile phones approached a GPS–GSM-collared bear. Spatial locations of the bear and the approaching persons are displayed on the digital map on the computer screen in real-time. The dispersion of spatial information was 2.5 m, and the success rate in the experiments was 81.2% (new spatial locations successfully received when requested). The method proved to be useful and accurate enough to study the behavior of bears (e.g., escape initiation distance) in the proximity of humans. We believe the methodology presented will help researchers to better understand bear behavior and develop strategies to minimize negative bear–human interactions. Rapid data transmission creates new opportunities for animal tracking in general. We believe that the GPS mobile phone-based tracking will become the most cost-effective method for studying large animals in areas serviced by mobile phone networks.