The impact of Palm-oil milling activities on the water quality of Kolo Creek was investigated for a period of six months. A total of 60 water samples was collected from two designated sampling stations (oil-palm mill and control) along the creek and were analyzed for various parameters which included temperature, pH, dissolved oxygen (DO), total alkalinity, turbidity, salinity, electrical conductivity, oil and grease, Total culturable heterotrophic bacterial counts and total coliform Most Probable Numbers (MPN) among others, using standard methods. Temperature values obtained ranged from 24.5 to 28.5°C. Values of pH ranged from 5.3 to 8.2, turbidity ranged from 9.65 to 43.24 NTU, dissolved oxygen (DO) ranged from 2.4 to 5.84 mg/l, oil and grease ranged from 110 to 470mg/l, conductivity ranged from 167 to 913ms/cm, Total culturable heterotrophs ranged from 3.2 x 105 to 5.8 x 105 cfu/ml, Total coliform most probable number (MPN) ranged from 20/100ml to over 180/100ml. The total coliform MPN expressed as a percentage of total heterotrophs in the oil palm mill station was 2.32%. Generally, values for the parameters determined with the exception of DO, chloride, salinity, and total coliform MPN, were higher for the oil-palm mill station than for the control station. Analysis of variance using paired t–test for the mean values obtained showed that with the exception of temperature, pH, total alkalinity, phosphate, salinity, and total coliforms, there was significant difference at p=0.05 level in all other parameters determined. Bacterial types and their frequency of isolation form the palm oil milling station were Bacillus sp (41.7%), Escherichia coli (16.7%), Klebsiella sp (8.33%), Proteus mirabilis (8.33%), Pseudomonas sp (8.33%), Staphylococcus aureus (8.33%), and Streptococcus sp (8.33%). While the bacteria form the control station were Bacillus sp. (66.67%), Proteus mirabilis (16.67%) and Streptococcus sp (16.67%). The low levels of DO, high levels of total dissolved solids, oil and grease, high bacterial counts including total coliforms and the presence of faecal indicator bacteria such as E. coli in the oil-palm mill station suggest that the Palm-oil milling activities impacts negatively on the water quality and on the aesthetics of the Creek water.