|The experiment was carried out to determine the use of double strength fumigation with formaldehyde gas on broiler breeder’s eggs hatchability, candling, blasting/putrification, dead in shell, quality of chicks and later life mortality. The broiler breeders eggs were divided into two groups each (n=134640 eggs). The fumigation of both groups was performed through automatic fumigation system provided by chick master. The hatchability and candling of flocks SSR1AIC, SSR2AIB, SSR3AID and SSF5 were significantly (P<0.05) better for double strength fumigation compared to single strength fumigation. The dead in shell were insignificant for the treatment. The putrification/blasting and low quality chicks were significantly (P<0.05) better for double strength fumigation for SSR2AIB, SSR3AID and SSF5, while remaining flocks were insignificant regarding quality of chicks and putrification due to fumigation strength. The chicks each (n=30,000) were shifted to poultry houses from both groups to know the effects of fumigation strength on later life of chicks. The weight gain, feed intake and FCR were insignificant for both groups while mortality was significantly better for double strength fumigation compare to single strength fumigation. In short double strength fumigation is safe can be used to improve the hatchery parameters and later life of chicks,