This work is focused on serious and fatal accidents which occur at forestry, agricultural and green maintenance working sites. In these sites are performed operations related to tree cutting or felling with continuous use of chainsaws. During this study we investigated 123 professional as well as non-professional working sites. We considered all characteristics necessary to determine the operating conditions and to identify possible steps for an effective protection. The work highlights a very serious situation in both investigated working environments where all measures of job safety are systematically ignored. In conclusion, we recommend that for a significant reduction of serious and fatal accidents, a mandatory training should be extended to all chainsaws users. Passive and active safety systems which interrupt the operation of the saw when it does not comply with all obligatory safety rules (i.e. human vicinity to cutting chain, falling down of the operator and others) should be defined