Objective: To evaluate the levels of interleukin-1ß (IL-1ß) and alkaline phosphatase (ALP) in gingival crevicular fluid (GCF) and correlate these measurements with clinical characteristics of healthy patients and patients with gingivitis and periodontitis. Method and Materials: Thirty-six individuals were subdivided into three groups of 12: control, gingivitis, and periodontitis groups. GCF samples were obtained from 2 sites for each patient. GCF volume was measured with the Periotron 8000; IL-1ß levels were evaluated using the ELISA technique; ALP was measured by the kinetic method. Results: Mean levels of IL-1ß and ALP in the 3 groups were, respectively, 22.34 ± 16.53 µL/site and 7.68 ± 2.46 U/L in the control group; 41.46 ± 27.98 µL/site and 9.80 ± 1.53 U/L in the gingivitis group; and 105.97 ± 89.26 µL/site and 11.56 ± 1.82 U/L in the periodontitis group. The amount of IL-1ß in the periodontitis group was significantly higher than in the other groups, but no significant difference was found between the control group and the gingivitis group. The amount of ALP differed significantly among the 3 groups (P .05). A positive correlation was observed among IL-1ß levels, GCF volume, and probing depth. There was no evidence for a correlation between IL-1ß and ALP levels. Conclusion: Monitoring immune markers may give additional information on healthy or diseased sites. Keywords: alkaline phosphatase, cytokines, gingival crevicular fluid, inflammation, interleukin 1, periodontitis