Aim of study was to examine periodontal status among 20 44 year old patients and to study the secretory function of peripheral venous blood neutrophilic leukocytes (NL) exposed to various antigens and alkaline phosphatase (AP) activity in gingival crevicular fluid (GCF) in patients suffering from gingivitis and periodontitis. Clinically were determined Russell's periodontal index (PI). Secretory function of NL affected by opsonized zymosane, non-opsonized E. coli was examined in 77 patients with gingivitis and periodontitis, and in 35 donors, free of internal diseases, by means of beta-glucuronidase (beta-GD), lysozyme (LZ). NL secreted higher levels of beta-GD in incubation medium in patients with periodontitis (p < or = 0.001) subject to degree of periodontal lesion. NL affected by various antigens secreted higher levels of LZ into non-cellular matrix in patients with gingivitis and periodontitis comparing to control environment in analogous groups. Data obtained from this study suggest that in patients with periodontitis response of NL to bacterial stimuli is specific and subject to the degree of periodontal lesion. Our study showed a significant difference of AP activity in GCF subject to pocket depth and degree of periodontal lesion. Once NL are exposed to corpuscules prone to phagocytosis, an increase in secretion of beta-GD and LZ can be explained by overall increase in secretion of NL lysosomic enzymes, thus disclosing the mechanism of inflammatory periodontal tissue damage.