Laundry services continue to increase along with the increase in community activities. The growth of laundry services has an impact on increasing the amount of detergent usage and laundry waste. One of the wastewater treatment is by aeration. The purpose of this study is to determine the effectiveness of aeration methods in reducing Biochemical Oxygen Demand (BOD) Oliv Laundry Jaya wastewater. This type of research is quasi-experimental. This research was conducted by conducting aeration on laundry wastewater with a time difference of 30 minutes, 60 minutes and 90 minutes for a sample of 1 liter and an air transfer rate of 5 liters / minute. This research was carried out with six replications. The ability of the aeration method in decreasing BOD of laundry wastewater was tested with ANOVA with sig 0, 000 shows that there is a difference in the effectiveness of decreasing BOD laundry wastewater with aeration treatment of 30 minutes, 60 minutes and 90 minutes. The conclusion of this research shows that aeration of wastewater for 90 minutes is the most effective contact time to reduce BOD of wastewater laundry