ABSTRACT   Background: Control of coccidiosis depends, in addition to the commercial preparation of herbal extracts, on good sanitation and litter management, along with the use of medication or vaccination programmes. In addition to the chemotherapeutic treatment of coccidiosis early disinfection of the poultry houses should be done using various disinfectants for controlling presence of oocysts.The objective of this research was to evaluate in vitro the action of four different coccidicidal disinfectant including (Quaternary ammonium compounds QACs, chlorocresol, glutaraldehyde and kilcox) on oocysts ofEimeriatenella. Methods: In this study the action of four coccidicidal disinfectant including (Quaternary ammonium compounds QACs, chlorocresol, glutaraldehyde and kilcox) on both sporulated and unsporulatedoocysts ofEimeriatenella was evaluated in vitro. E. tenellaOocysts were obtained from naturally infected Egyptian native breed chickens. The oocysts were exposed to the disinfectants at different concentrations and different contact times. The efficacy of the disinfection was assessed by either destruction of sporulatedoocyst or inhibition of sporulation.Results: It was observed that the most efficacious disinfectants against unsporulated and sporulatedE. tenellaoocystswaskilcox followed by chlorocresol, while QACs and, glutaraldehyde were less effective. kilcox sporulation inhibition reached 100 % on unsporulatedE. tenellaoocysts,and their destructive effect reached 99% on  sporulatedoocysts. furthermore, the results showed that both inhibitory and destructive activity of the tested disinfectants was significantly increased by increasing their concentrations and/or the contact time.