- BEGACH Running Club
- BEGACH is a running club based in Sofia that organizes a variety of races every year as well as the running seminar Fizkultura every spring. (Full disclosure I am a member)
- Trail Series (Bugarian)
- The Series that got me into trail running, they offer a trail race once a month in the vincinity of Sofia in one of three distances 5k, 10km and 15km+. They also organize the Pirin Skyrun and Vertical Kilometer in July.
- 5km Run (Bulgarian)
- Offers weekly free 5km Park Runs in Sofia (2), Plovdiv, Burgas and Varna. They reward their consistent participants with a series of t-shirts based on your total run distance. They also organise a other runs called XLkmRuns that vary in terrain and location. At the moment the XLkmRuns are all located in the Sofia Area.
- iRun (Bulgarian)