Background The aim of this study was to determine some epidemiological aspects of motorcycle user traffic fatalities including the crash mechanisms and injury patterns in East Azerbaijan, Iran (2006-2016). Methods A total of 1840 motorcycle user mortal cases registered in East Azerbaijan forensic medicine database, in Iran, were analyzed over the time period between March 2006 and March 2016. The distribution and associations of both victim- and crash-related variables such as crash mechanism, types of involved vehicles, types of injuries, and demographic characteristics were investigated. Data were analyzed by Stata v.13 statistical software package. Results Of the 9435 RTI deaths, 1840 (19.5%) were motorcycle users of whom 96.5% were male (mean age of 32.3 ± 18.5 years). The majority of accident mechanisms were motorcycle-vehicle crashes (77.8%), followed by rollover (11.8%). Cars were the leading counterpart crash vehicle comprising about 34.8% of the motorcycle user mortalities. Inner city traffic injuries were the reason for 744 (40.7%) of the motorcycle user mortalities. Head trauma was the main cause of death. About 82% of the victims were motorcycle riders and the remainder were pillion passengers. A decreasing trend of fatal traffic accidents was observed over the study period for both the motorcycle user fatalities and other traffic injuries. The percentage of motorcycle mortalities over all traffic mortalities had a decreasing trend over the past nine years from March 2007 to March 2016 reaching a figure as low as 15.2% through the last year of study. Conclusions Motorcycle traffic fatalities, although having a decreasing trend during the last decade with a better slope than most other traffic injuries, remain to be a major public health in north-west of Iran. There is a need for effective interventional programs to reduce the burden of motorcycle fatalities.