Propylene glycol methyl ether was removed from wastewater in a trickling bed bioreactor under different liquid distribution conditions. A 0.3 m diameter column filled with two heights of 0.7 m and 1.4 m with 2 cm plastic spheres with were used. The wastewater flow rate varied from 0.184 to 0.918 kg/m 2.s. The effect of the initial liquid distribution was examined using two types of liquid distributors: a multipoint liquid distributor and a central single point liquid distributor. Over 96 hours of treatment period, the BOD 5 was reduced by 85% and 65% under the most uniform liquid distribution condition and the poor liquid distribution condition, respectively, achieved in this study. Increasing the liquid flow rate from 0.184 to 0.918 kg/m 2.s, it increased the dynamic liquid holdup by 53% and the apparent BOD5 removal rate constant by 23% at 1.4 m bed height using the multipoint liquid distributor. Moreover, with the use of the multipoint liquid distributor, the apparent reaction when the liquid flow rate was increased from 0.184 kg/m2.s to 0.918 kg/m2.s. In addition, it was found that the effect of an increase in the bed height on the percentage BOD5 removal was not significant when initial liquid distribution was uniform. Under the uniform initial condition, only 4% increase in the percentage BOD5 removal was observed when the bed height increased from 0.7 to 1.4 m whereas when the initial distribution was extremely non-uniform, the percentage of BOD5 removal was increased by 20% with increasing the bed height. The local distribution of the BOD5 removal was not uniform across the bed cross-section and it was affected by the liquid flow distribution across the bed cross-section.