Equipment and machinery used in Agricultural field produce sounds with wide spectrum. Therefore operators and other workers exposed to these sounds. In this study, effects of some factors on emitted noise of a Honda GXV 160 power lawn mower in three different distances were studied. The experiments were carried out based on a factorial statistical design in the form of randomized complete block design with four replications. Sound level measuring device and their establishment and set up were selected in which according to acquired data, the emitted noise level of power lawn mower could be calculated. The results showed that, there exists a significant relationship at 99% levels of probability between the levels of blade rotational speed and emitted noise. But no significant relationship was observed between the levels of collecting basket, operation type and emitted noise. Also results reveal the great sound level at operator’s ear position in comparison with other positions. According to permitted exposure noise level, the received noise level of operator was hazardous and using of hearing protection devices is mandatory. But the received noise level of other workers in field was not hazardous.