The aim of our study was to determine the rate of elevation of c-reactive protein in cancer patients and to evaluate its correlation with other acute phase proteins. A total of 104 patients with various types of cancer who admitted clinic were included in our study. Serum levels of c-reactive protein, lactate dehydrogenase, ferritin, haptoglobin, plasma fibrinogen levels and erythyrocyte sedimentation rate were measured. The serum levels of c-reactive protein was found to be increased in 74% of cancer patients, with 81.3% and 64.4% in metastatic and non-metastatic group, respectively. Our study showed that c-reactive protein and fibrinogen demonstrated better characteristics than other acute phase proteins to differentiate between cancer patients and healthy individuals and also to differentiate between healthy individuals and patients with infection. C-reactive protein, ferritin, fibrinogen, erythrocyte sedimentation rate, and haptoglobin showed similar characteristics to differentiate metastatic and non-metastatic cancer patients whereas, LDH demonstrated the lowest performance. C-reactive protein was not found to be superior to other acute phase proteins in the differential diagnosis of cancer and infection and in differentiating early stage disease from advanced stage.