The transverse sinuses were studied on the pertechnetate brain scans of 212 patients. The symmetry or asymmetry of the transverse sinuses was determined in the posterior and lateral views. The sinuses were equal and symmetric in 15.1 per cent. A prominent right transverse sinus was found in 55.6 per cent, and a prominent left transverse sinus was found in 29.3 per cent. In 22.2 per cent of the total number of scans, the usually barely seen occipital sinus was very prominent and dense. The largest number, 28 studies, of extra large occipital sinuses drained into the prominent left transverse sinus. Central positioning of the torcula on the posterior scan is essential for adequate resolution of the transverse sinuses.