There is an ever-increasing demand for micro-components in areas of electronics, biomedical and microelectromechanical systems. Microinjection molding (µIM) has attracted considerable attention from both the industrial and academic spheres due to its potential for mass production of small polymeric components. However, most studies are only focused on unfilled plastics. Due to the very high shear rates present in µIM, polymer composites demonstrate issues with the filler distribution that may affect product properties depending on the filler purpose, i.e. structural, electrical or thermal conductivity. A specific mold which has a three-step configuration along the flow direction was adopted to study the effects of abrupt changes in mold geometry on filler distribution. This study is focused on the effect of high shearing conditions on the resultant properties of polystyrene/carbon nanotubes (PS/CNT) composites with special emphasis on electrical conductivity and filler distribution within the matrix. The effect of processing parameters such as injection velocity and melt temperature was investigated using design of experiments method. Results revealed that the electrical conductivity is process variable dependent and melt temperature is the dominant influencing factor. The percolation threshold of the obtained micro-components falls in the range of 5~7 wt%, with samples indicating an orientation of CNT in the flow direction, which was corroborated by morphology observation and simulation analysis.