Objective: The aim of this study was to evaluate and compare the antibacterial effect of chlorhexidine and calcium hydroxide slow-release devices on oral bacteria. Method and Materials: The agar diffusion test was used to evaluate the antibacterial effect of the slow-release devices Activ Point (chlorhexidine; Roeko) and Calcium Hydroxide Plus Point (Roeko) on 8 anaerobic and 2 facultative oral bacterial strains, as well as 2 bacterial cultures randomly sampled from necrotic root canals and incubated in anaerobic and aerobic broth for 48 hours. The efficiency of the medicaments against the various strains was evaluated using a nonparametric test (Friedman type) and a second nonparametric test (Wilcoxon's signed rank test). Results: Activ Point produced significantly larger inhibition zones (P .001) than the calcium hydroxide slow-release device around all tested bacterial strains. Conclusion: The chlorhexidine slow-release device (Activ Point) exhibited significant antibacterial activity in the agar diffusion test and merits study as an intracanal medicament. Schlagwörter: agar diffusion test, calcium hydroxide, chlorhexidine, slow-release device