Ground water is the most valuable natural water resource to the people in Bachok for the dependence on this source. This paper discusses to what extent the differences of the ground water quality in the research area with the National Drinking Water Quality standard guidelines 1983. For three years the data of the ground water quality were used to observe the differences occurred that is in 1990, 1999 and 2011. The parameters for Chloride (Cl), Nitrate (NO3), Ammonia (NH4), Ferum (Fe), Manganese (Mn), Sodium (Na), Potassium (K), Calcium and Magnesium (Mg) are used to compare with the standard that has been set by the Ministry of Health Malaysia (MOH) in the chart form. The results of this study found that almost all the ground water parameters in the well in Bachok exceed the national drinking water standard, such as Chloride (Cl), Ammonia (NH4), Ferum (Fe), Manganese (Mn) and Potassium (K). Three more parameters which are Sodium (Na), Nitrate (NO3) and Magnesium (Mg) were found that only in some wells exceed the drinking water standard 1990. Although there are still wells that exceed the standard, the most recent data in 2011 showed a decline compared to 1990 and 1999. Monitoring action and drastic measures must be taken to ensure the quality of the drinking water in Bachok is safe to be used.