Nipa (Nypa fruticans Wurmb) sap/sugar production has been practiced sustainably over a hundred years in southern Thailand. Farming techniques such as tapping were established over the times, however the variation of sap/sugar production and its regulating factors are not yet fully recognized. The daily sap yield and the sugar content were monitored for three years (2010, 2011 and 2012) in 7 nipa farms. The daily sap yield varied from 0.02 to 2 litres per fruit stalk with the sugar content ranging from 10.6 to 28.6%. The duration of sap production from the same fruit stalk was from 20 days to 56 days and the mean sugar content of 1,892 measurements was 18.1%. Although the density of the fruit stalks was of minimal significance, the growths of the fruit stalk were significantly related to sap production. Thicker and longer fruit stalk produced more sap. Water inundation affected the growths of the fruit stalk resulting in a decrease in sugar production 4 to 5 months after the rainy season. Nipa farms in the study site produced sugar at the rates of 3.2 to 6.5 tons/ha/year nevertheless farm management to increase growths of fruit stalk and to reduce impact of water inundation could enhance nipa sap/sugar production.