Background: Lower limb cellulitis is an infectious disease that has serious complications unless it is treated. Objectives: In this pilot study, we evaluated whether levels of YKL-40, an acute-phase reactant, and mean platelet volume (MPV), which occurs secondary to inflammation in cellulitis, increase compared to healthy subjects. We also aimed to investigate the association between YKL-40 and MPV in the prognosis of the patients. Material and Methods: A total of 55 patients with cellulitis (23 men and 32 women) and a similar age group of 46 healthy individuals (22 men and 24 women) were included in the study. Cellulitis was diagnosed according to guideline. Serum YKL-40 levels, MPV, C-reactive protein (CRP), and other biochemical values of both groups were compared. Results: YKL-40 levels (52.2 +/- 34.5 ng/mL vs 34.6 +/- 18.0 ng/mL, P = 0.004), MPV (7.7 +/- 1.0 fL vs 6.9 +/- 0.7 fL, P < 0.001), and CRP (9.5 +/- 8.2 mg/dL vs 0.7 +/- 0.6 mg/dL, P < 0.001) were significantly higher in the patients with cellulitis than the control. The mean recovery time (RT) of the patients was 22.6 +/- 6.9 days. We found that YKL-40 (odds ratio [OR] 0.1, confidence interval [Cl] 0.028-0.191, P = 0.009) and MPV (OR 2.4, Cl 0.254-4.578, P = 0.029) have an independent association with RT. Conclusion: YKL-40 and MPV values were correlated with higher CRP in the cellulitis group than in controls. According to these results, increased YKL-40 and MPV levels might be a prognostic factor for cellulitis in patients.