All around the world, ประสิทธ (Prasit 
, ประสิทธ ) is quite a rare male forename. The forename ประสิทธ is habitual in Thailand, where it is quite a rare boy's name, Singapore, where it is a rare male name, and India, where it is a very rare predominantly male, but very infrequently feminine name. Not in comparison with a country's population, this name is the most popular in Thailand, India, and the United States. Very seldom, ประสิทธ is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Prasit | Indonesia, Nepal, India, Thailand, United States |
| ประสิทธ | Thailand |