Ethyl-acetic extract of rambutan (Nephelium lappaceum L.) peel has been studied for its fermentation inhibitory effect, whereas Ca(OH)2 has been reported for its ability to increase pH value due to its alkalinity. This research was aimed to investigate the effect of incorporation of ethyl-acetic extract of rambutan peel and Ca(OH)2 into sugar palm neera to delay alcoholic fermentation and maintain pH of sugar palm neera for palm sugar production. Treatments of ethyl-acetic extract of rambutan peel (0, 1, 2, 3%, w/v, db) and Ca(OH)2 (0, 0.05, 0.075%, w/v) were applied into sugar palm neera and let ferment for seven days. Physicochemical characteristics, such as pH, total titratable acidity, total dissolved solids, total sugar content, total reducing sugar, and alcohol content, were determined on day 0, 1, 2, 3, 4, 5, and 7, while microbial enumeration was determined on day 0, 1, 3, 5, and 7. The alcoholic fermentation of several treated samples was found to be completely inhibited (alcohol content 0.00-0.03±0.03%) up to seven days of fermentation. Treatment of 0.075% Ca(OH)2 and 2% extract after one day of fermentation gave the best effect in maintaining pH value (pH 6.18±0.21) of sugar palm neera. These results proved that ethyl-acetic extract of rambutan peel combined with Ca(OH)2 were able to successfully delay alcoholic fermentation and maintain pH value. Six samples were then selected based on its high total sugar content to be processed into palm sugar in research stage II. Palm sugar produced from neera with treatment of 0.075% Ca(OH)2 - 2% extract - day 5 had more often than so superior and/or similar quality in terms of the parameters analyzed, as compared to other treatments. As compared to control, it had better total sugar content and texture.