Introduction: Electrolytes are very essential for normal functioning of vital organs including heart. Electrical activity of the heart is regulated by Na, K and Ca. Normal homeostasis of these electrolytes are vital for normal functioning of heart. Electrolyte imbalance is often common after episode of acute coronary syndrome (ACS) and electrolyte imbalance may have important role in altering the prognosis of ACS. Aims & Objectives: To assess the serum electrolytes imbalance (Na, K and Ca) in ACS patients within first 48 hours of onset of symptoms. Materials and Methods: This hospital based cross sectional study conducted on 50 cases of ACS and 50 healthy controls. Serum Na, K and Ca (total) concentration were estimated in healthy controls and newly diagnosed cases of ACS within 48 hours of onset of symptoms. Result: Mean value of serum Na, K and Ca (total) in case and control group were 138±4.23 and 140±1.99 mEq/L (p=0.0018), 3.87±0.43 and 4.16±0.35 mEq/L (p=0.0006), 8.85±0.59 and 9.68±0.44 mg/dL (p<0.0001) respectively. Hyponatremia, hypokalaemia and hypocalcemia were found in 14% (n=7), 12% (n=6) and 18% (n=9) of ACS patients respectively. Conclusion: There were statistically significant lower levels of serum Na, K and Ca (total) found in ACS patients compared to healthy controls.