The efficacy of nisin (25-75 ppm) and effect of storage time on quality attributes of micro-filtered coconut water during refrigerated storage (4°C) for 8 days was investigated in terms of total viable counts, colour, turbidity and overall sensory acceptance. All treatments significantly retarded the bacterial growth in coconut water during storage when compared to the control sample (p < 0.05). The samples treated with 50 and 75 ppm nisin had significantly lower aerobic microbial counts than the control (p < 0.05) without affecting colour, turbidity and sensory acceptability. The treated samples also had the significantly higher scores in overall acceptance than the control sample after 7 days of storage.50 ppm Nisin was suggested to be applied in micro-filtered coconut water without effects on colour, turbidity, and sensory acceptability by a reduction in changes of the microbial growth during the refrigerated storage.