We investigated the role of delayed cerebral maturation, hemisphere asymmetry and regional differences in children with stuttering and healthy controls during resting state and hyperventilation, using conventional EEG techniques and quantitative EEG (QEEG) analysis. This cross-sectional case control study included 26 children with stuttering and age-sex matched 21 children with no history of stuttering. Visual EEG revealed significantly higher parieto-occipital slow waves and slower fronto-central asynchronic waves in the stutterers than in the controls. QEEG analysis showed significantly increased delta activity, especially in the right frontal and parietal regions and decreased alpha frequency in the bi-frontal regions of the stutterers, compared to the controls. Results are discussed in terms of the maturation hypothesis, especially nondominant frontal lobe (possibly supplementar motor area) and parietal lobe functioning.