This study investigated the correlation between antihypertensive medication and the effect of post-operative rehabilitation in elderly hypertensive patients. We performed a retrospective analysis of 158 elderly hypertensive patients receiving antihypertensive medication after surgery for femoral neck fracture in Takaoka City Hospital from April 2012 to March 2015. We divided the patients into three groups: 51 patients with systolic blood pressure (SBP) more than 121 mmHg at the end of rehabilitation in our hospital, 84 patients with SBP between 101 mmHg and 120 mmHg, and 23 patients (hypotensive group) with SBP lower than 100 mmHg. The better rehabilitation effect after surgery for femoral neck fracture was observed in the group of SBP more than 121 mmHg compared to the hypotensive group. In the hypotensive group, significant increase in the rate of hyponatraemia was observed, and the rate of taking-diuretics and blood-transfusion was highest. There was no significant difference in age, bodyweight and serum albumin level. These results suggest that avoiding excessive hypotension and hyponatraemia is important in elderly hypertensive patients taking diuretics in order to attain better rehabilitation effects after surgery for femoral neck fracture.