This study was designed to assess the blood electrolytes (Sodium, potassium, chloride, calcium and phosphate) levels in some hypertensive patients and healthy volunteers and to compare between them. The study aimed to determine possible changes in electrolyte levels of hypertensive patients in University of Port Harcourt Teaching Hospital. The study population was a randomly selected total of 120 healthy staff and student adults between 18-50 years of the University community and 120 patients of the University teaching hospital. 5mls of blood sample were collected separately from ante cubital vein of each of the study subjects. The serum electrolytes determined were sodium, potassium and chloride (Ion Selective Electrode method); calcium (Randox method) and phosphorus (Phosphomolybdate method).  Measurements of results were analyzed using statistical package for social science (SPSS) version 17.0. The mean values of potassium and chloride in hypertensive female patients were lower compared to those of control, while sodium and calcium showed no significant difference. The male category showed significant lower values in sodium, chloride and calcium while Phosphorous were higher in the hypertensive patients in both categories when compared to the healthy volunteers (control). The results obtained showed a significant difference at p < 0.05 significant level between hypertensive and healthy individuals for various blood electrolytes in both female male categories. We can then conclude that hypertensive patients and healthy individuals blood electrolytes is significantly different.