Motorcyclists constitute a vulnerable type of road users. Although much research has been conducted in this topic, still much effort is needed to understand the accident mechanisms of motorcycle accidents. Therefore, the present paper aims to investigate the critical factors of motorcycle accidents in Greece, by utilizing data for the period 1985-2011. For that reason, loglinear regression models were developed in order to investigate the influence of several parameters such as area type, driver age, lighting conditions and accident type on fatalities, severe and slight injuries of motorcyclists. Comparisons with accidents involving passenger car drivers are also carried out. The findings of the study indicate that the number of vehicles involved in the accident is the most significant factor in the fatalities model. On the other hand, the accident type seems to have a greater effect on the number of severe and slight injuries. This effect was found to be greater for motorcyclists than for passenger cars drivers. The findings of the study could be used to shed light on the factors affecting motorcyclists’ fatalities and injuries and thus enhance their safety by considering appropriate policy measures.