Our aim was to determine the levels of arginine decarboxylase (ADC), ornithine decarboxylase (ODC) and agmatine, ornithine, nitric oxide (NO) and arginase activity in the acute and subacute phases of acute ischemic stroke (AIS), by revealing the possible role of these levels in neuroinflammation and neurogenesis that are postulated to begin after AIS. 35 patients diagnosed with AIS and 35 controls were included in the study. ADC, ODC, agmatinase and NO levels were determined by ELISA kits. Arginase activity and ornithine levels were measured spectrophotometrically. There was no statistically significant difference between the levels of agmatinase, ornithine and arginase activity on days 1 and 7 in the AIS group and the levels measured in the control group (p> 0.05). High ADC and low ODC and NO values were found in the patients compared to the controls in both acute and subacute periods (p< 0.05). It was shown that polyamine synthesis decreased in both acute and subacute periods after AIS; and this was due to the decrease in ODC levels, the rate-regulating step of the major pathway. This reduction may be associated with both the inadequate stimulation of neurogenesis and the immune system with reduced NO synthesis. Keywords: polyamine synthesis enzymes, ornithine, ornitine decarboxylase, nitric oxide, arginine decarboxylase, agmatine, agmatinase, arginase activity, neuroinflammation, neurogenesis, immune system, acute ischemic stroke.