Abstract: A nested Polymerase Chain Reaction (PCR) assay, for detection of intact and calcified hydatid cysts of Echinococcus granulosus (EG)-complex, was developed and evaluated. The NADH dehydrogenase 1 gene was used as a target DNA for PCR amplification. Two pairs of primers, (EGL 1 and EGR 2) and (EGL 3 and EGR 4), were designed and used in 2 amplification steps. First, the outer pair of primers (EGL 1 and EGR 2), derived from a highly conserve region of NADH 1 gene produced a primary 435 base pair (bp) PCR product from different stains of EG-complex including, sheep strain (genotype) designated (G 1), Cattle strain (G 5), camel strain (G 6) and pig strain (G 7). Second, a pair of internal (nested) primers (EGL 3 and EGR 4), designed internal to the annealing sites of primers (EGL 1 and EGR 2), produced a 276 bp PCR product. The primary 435 bp and the nested 276 bp EG specific PCR products were easily identified following visualization onto an ethidium bromide-stained agarose gel. However, the primary or the nested PCR products were not amplified from DNA extracted from Cysticercus tenuicollis and Coenurus cerebralis, the larval stages of the adult dog cestodes Taenia hydatigena and T. multiceps, respectively. The described nested PCR assay could be used to detect sheep, cattle and camel strains of EG-complex circulating in Sudan. This PCR assay could also, be used for rapid detection and differentiation of EG-complex from other related cestodes. This assay should be considered during an epidemiological survey of the disease in areas of endemicity.