Objective To compare the reproducibility of probing depth (PD) measurements using the Florida probe and the conventional periodontal probe.Methods Before and after initial periodontal treatment, five patients with chronic periodontitis received repeated PD measurements using the Florida probe and the conventional periodontal probe, respectively. The reproducibility of PD measurements was compared between the two different probes. The reproducibility of PD measurements using the same probes was also compared before and after the treatment.Results The reproducibility of PD measurements with both of these probes was good (P~0.05 , r=~0.77 ~~0.85 ) for both before and after initial treatment. Before the treatment, the reproducibility of these two probes was similar. After treatment, the reproducibility of the Florida probe was better than that of conventional periodontal probe (P~0.05 ).Conclusion The reproducibility of PD measurements with the Florida probes is reliable, suggesting that it can be applied in clinical research.