Background To explore a new method of kidney biopsy with coaxial trocar and bard biopsy gun under low dose computed tomography (CT)-guidance and evaluate its accuracy, safety, and efficacy. Methods Sixty patients underwent renal biopsy under CT-guidance. They were randomly divided into two groups: group I, low dose CT-guided (120 kV and 25 or 50 mAs) and group II, standard dose CT-guided (120 kV and 250 mAs). For group I, the coaxial trocar was accurately placed adjacent to the renal capsule of the lower pole, the needle core was removed, and samples were obtained with a bard biopsy gun. For group II, the coaxial trocar was not used. Total number of passes, mean biopsy diameter, mean glomeruli per specimen, mean operation time, mean scanning time, and mean radiation dose were noted. Dose-length product (DLP) was used to calculate the radiation doses. After 24 hours of the biopsy, ultrasound was repeated to identify any subcapsular hematoma. Results Success rate of biopsy in group I was 100% while using low dose CT-guidance along with coaxial trocar renal. There was no statistic differences bewteen group I and II in the total number of passes, mean biopsy diameter, mean glomeruli per specimen and mean time of operation and CT scanning. The average DLP of group I was lower as compared to the value of group II (p <0.05). Conclusions Kidney biopsy using coaxial trocar and bard biopsy gun under low dose CT was an accurate, simple and safe method for diagnosis and treatment of kidney diseases. It can be used for repeat and multiple biopsies, particularly suitable for obese and renal atrophy patients in whom the kidneys are difficult to image.