Injuries and deaths due to road traffic crashes (RTC) are major public health concern. The Road Traffic Injury Research and Prevention Center, collects RTC data on injuries and fatalitiesfrom five emergency departmentsin Karachi. Data generating process (DGP) for RTC from 2007 to 2014, for monthly number of fatal and injured victims were analyzed using autoregressive integrated moving average and vector auto regression, time series models. Results provide strong evidence that the DGP for the current levels of the number of fatalities and injured owing to RTCs are significantly influenced by the own past history of the two series. The analysis with the impulseresponse function also indicated that there is a slight seasonality pattern in the number of injured and fatalities. The similar behaviour and association of the two variables suggest that certain conditions e.g. road conditions, weather, volume of vehicles, and accidents might be persistent in time in Karachi.