We describe the clinical features and electromyographic findings of two patients who had childhood onset nemaline myopathies, confirmed by muscle biopsy. This autosomal dominantly inherited myopathy is characterized by the presence of rod-shaped bodies within muscle fibers and the predominance of type I fibers with concomitant atrophy. In addition to diffuse weakness and hypotonia, the clinical features include and elongated face, a highached palate, kypho-scoliosis, pes caves and talipes equinovarus. This myopathy can present at any age and can be divided into three groups, such as the severe neonatal form, a milder childhood form and an adult form. EMG findings in nemaline myopathy has usually show "myopathic" features, but normal or even patterns compatible with "neuropathy" are also shown. Electromicroscopic features consist of the accumulation of nemaline bodies under the sarcolemma and between the myofibrils, and enlargement and streaming of the Z disks. The rods appear to originate from the Z disks and the weakness seems to be related not to the nemaline bodies but to the Z disk alteration.