The effect of different parameters on the residence time distribution of a Taylor flow microreactor was investigated. The reactor residence time distribution was calculated from the tracer residence time distribution of a single unit cell. It was found that generally an increase in Bodenstein number, capillary number or slug length increased the spread of the residence times. A case study comparing the effect of two different sets of design and operating parameters on the distribution spread showed that spreading can be minimized by careful choice of parameters, in particular slug length.