Abstract: Natural rubber latex waste filled with water hyacinth was used as adsorbent as a part of the waste alternative utilization. This study was aimed to determine the maximum contact time and pH of the adsorbent on the adsorption process of grease in water. It was carried out by contacting the adsorbent with the mixture of grease and water for 5-25 min with the addition of different pH solution. It was found that the adsorption capacity of the adsorbent was improved with the increasing contact time while the increase of pH solution showed no significant effect on the adsorption capacity.