Background Traffic events where motorcyclists are involved are a phenomenon increasingly frequent in Mexico. The use of less fuel and the practical to drive this vehicle makes the motorcycle a convenient mean of transport for a large sector of the population. For this reason, the objective is to analyse the associated factors to severe injuries of motorcyclists involved in traffic events in the Guadalajara metropolitan area and the municipality of Zapotlanejo in Jalisco, Mexico.

Methods This is a cross-sectional study made to injured motorcyclists in the Guadalajara metropolitan area and the municipality of Zapotlanejo who were care in the Antiguo Hospital Civil de Guadalajara “Fray Antonio Alcalde”. The people selected were drivers or occupants of the motorcycle crashed, of any sex and age and the traffic event in what they were involved. A model of logistic regression was performed, which included the above variables with a p = <0.25.

Results The risk factors for severe injuries were: the motorcycle does not work correctly before the accident (OR 76.89, 2.08–2839.25), the motorcyclist deemed to have committed a traffic violation at the time of the event (OR 6.88, 1.30–36.26), the injured resident in the Guadalajara metropolitan area (OR 7.58, 1.15–50.17), drive a motorcycle unknowing if was “salvage” or not (OR 6.88, 1.30–36.26). The factors that reduce the risk were: drive other motorcycle except Italika (OR 0.06, 0.008–0.41) and have had the crash in a straight road or in a crossroad (OR 0.10, 0.02–0.61).

Conclusions There are elements of the motorcyclist, the motorcycle and the physical environment that increase or decrease injury severity of motorcyclists without health insurance. For this public health problem could be necessary promote and create more awareness about road safety in motorcyclists. Not only promote the use of helmet, require support other recommendations about motorcycle and physical environment.