In this paper, we present a straightforward analytical method for calculating the efficiencies of an click here ovoid shape (elliptical cylindrical) detector by using a randomly located point source.To determine the activity of an unknown radioactive source, absolute efficiency is required and we should take into account the attenuation skull bride and groom of the gamma-ray photons by the source container and the detector housing materials.The soundness of the resultant straightforward analytical method was successfully confirmed by comparison with some published data.