Introduction: Many middle-aged Turks go hiking in mountains to breathe some fresh air or to maintain fitness. Objective: This study investigated the effects of regular high altitude mountain climbing on the metabolic and hematological responses of mountaineers. Methods: Hematological and biochemical parameters were studied, as well as some hormonal values of 21 mountaineers and 16 healthy age-matched sedentary volunteers. Results: The neutrophil to lymphocyte ratio (NLR) was significantly lower (p<0.04) in mountaineers compared with the sedentary group. Total protein (p<0.001) and albumin (p<0.001) were lower, while the levels of ferritin (p<0.04), creatine (p<0.03) and creatine phosphokinase (p<0.01) were higher in mountaineers. Other hematological and biochemical parameters, i.e., erythrocytes, leukocytes, hemoglobin and hematocrit, did not change significantly. Conclusion: Our results show that regular exposure to high altitude increased the serum levels of some acute phase proteins with anti-inflammatory properties.