The aim of this study was to investigate the effect of apilarnil on haematological changes after exhaustive exercise. In the study, sham group (SH) in which no treatment was performed, control group (CN) in which saline was given orally, exercise group (EG) in which swimming exercise was performed for 30 min during the study and saline was given orally daily, exercise+apilarnil group in which swimming exercise was performed for 30 min. The exercise+apilarnil1 group (EGA1), in which swimming exercise was performed for 30 min and daily 200 mg/kg apilarnil was given orally as a supplement, and the exercise+apilarnil2 group (EGA2), in which swimming exercise was performed for 30 min and daily 400 mg/kg apilarnil was given orally as a supplement. After 1 week of acclimatisation exercise, the rats were subjected to experimental exercise for 2 weeks. At the end of the study, blood samples were taken from the rats. Leukocyte (WBC), lymphocyte (LYM), monocyte (MID), granulocyte (GRA), erythrocyte (RBC), haemoglobin (HGB), haematocrit (HCT), mean erythrocyte haemoglobin concentration (MCHC), mean erythrocyte haemoglobin (MCH), platelet (PLT) and platelet distribution width (PDW) levels were determined. Statistical analyses revealed significant differences between groups in WBC, LYM, MID, GRA, RBC, HGB, HCT, PLT, and PDW values, while differences in MCH and MCHC values were found not significant. These findings suggest that apilarnil may positively influence blood parameters in conjunction with exercise.