aim of the work Calprotectin (CalP) and myeloperoxidase (MPO) are biochemical markers in the gingival crevicular fluid (GCF). Their increased concentration indicates the onset of an inflammatory process. The aim of this study was to valuate the correlation between the levels of calprotectin and myeloperoxidase detected in the crevicular fluid (GCF) at different probing depth (PPD). Materials and methods In a total of 11 subjects with chronic periodontitis, non smokers enjoying good health and who had not undergone periodontal nor antibiotic therapy in the 6 months prior the study, 60 sites were randomly selected and bleeding on probing (BOP), PPD, quantity of GCF and concentration of MPO and CalP were recorded. The volume of GCF was assessed through inserting PerioCol paper strips in the periodontal pockets for 10 seconds, then analyzed with a micro-moisture meter electronic instrument (Periotrom 6000, Siemens). The determination of the CalP was performed by enzyme immunoassay. The determination of MPO in the crevicular fluid was performed using the spectrophotometric reading of optical density. The results were statistically analyzed (SPSS16). Results PPD 5 mm (GCF=0,72 μg/μl; CalP=10,06 μg/μl; MPO=3,69 μg/μl); PPD 6 mm (GCF=0,78 μg/μl; CalP=10,64 μg/μl; MPO=5,45 μg/μl); PPD≥7 mm (GCF=1,32 μg/μl; CalP=7,20 μg/μl; MPO=5,55 μg/μl). There were no statistically significant differences in the concentrations of MPO and CalP in the deeper periodontal pocket. Conclusion The concentration ofmyeloperoxidase seems significantly related to the increased presence of neutrophils into the deepest pockets.