Objectives: Weight gain in-between hemodialysis sessions is a significant factor associated with morbidity and mortality amongst patients on hemodialysis. We carried out this study to study the effect of post dialysis serum sodium levels on interdialytic weight gain. Methods: This cross-sectional study was carried out at Dialysis Unit of our hospital from January to February 2022. We included patients on maintenance hemodialysis for end stage renal disease and excluded those with poor compliance or unwillingness. Patients were selected by non-probability convenience sampling technique. During the midweek hemodialysis session, post- dialysis weight was recorded and blood sampled from arterial port of dialysis tubing for measurement of post- dialysis serum sodium levels. Pre- dialysis weight was measured on the next hemodialysis session to calculate the inter-dialytic weight gain. Relationship of serum sodium levels with interdialytic weight gain was assessed by linear regression. Results: This study was done on 69 patients aged 53.46± 14.50 years. There were 58 (84.06%) males and 11 (15.94%) females. Median interdialytic weight gain was 2 kg (interquartile range 1.25- 3.00 kg). This was ≥3 kg in 27 (39.14%) patients. Mean serum sodium levels were 137.80± 2.69 mmol/l. There was an insignificant correlation of serum sodium levels with interdialytic weight gain (R= 0.071; p= 0.562). Conclusions: Post- dialysis serum sodium levels are not related to interdialytic weight gain amongst patients on hemodialysis.