B Background According to the National Health and Nutrition Examination Hypertension surveys are the most common cause of the second stage of renal failure after diabetes mellitus. The purpose of this study was to determine the relationship between long periods of hypertension and a decrease in GFR at X Hospital, the method used was observational analytic method with design cross sectional in October - December 2013 which included 143 primary hypertension patients. Data was collected using medical records of primary hypertension patients in 2012-2013 at Tangerang X Hospital. Distribution of respondent characteristics including age, gender, length of time suffering from primary hypertension, BMI, initial GFR, final GFR, and the condition of GFR presented in percentages. The relationship between the duration of suffering from primary hypertension and the decrease in GFR values ​​using the Pearson correlation test. The level of significance used is <0.05. Results In the distribution of respondents' characteristics, the majority of respondents were male (58.7%), had primary hypertension <5 years (67%), had BMI18.50 - 24.90 kg / m2 (70.6%), initial GFR amounting to 60-90 ml / minute / 1.73m2 (46.2%), final GFR (51.7%), and respondents who experienced a decrease in GFR (52.4%). The results of the Pearson correlation test showed that most of the respondents suffered from short-term primary hypertension (<5 years) with no decrease in GFR (69.1%), and respondents who suffered from long-term primary hypertension (≥ 5 years) with decreased GFR (97, 8%). Pearson correlation test found a significant relationship between the duration of hypertension and a decrease in GFR value (p = 0.000 *) Conclusion There was a relationship between the duration of primary hypertension and the decrease in GFR in Tangerang X Hospital.