The concentrations of Cu, ceruloplasmin, Mg and S in the blood serum of eight patients with meningioma were significantly higher than the normal levels. Ca, P, Cu, Mg, Na and K contents in the tumour itself of the same patients plus one were compared with the concentrations in the normal dura mater of human brain. The contents of all elements were significantly increased, except the mean Ca in six meningotheliomatous or fibroblastic meningiomas when this group was studied apart. The psammomatous tumours had higher concentrations of Ca, Cu and Mg than the other histologic types. No significant correlation was found between the concentrations of the element in the neoplastic tissue and the duration of symptoms or the tumour size, except a negative correlation between Cu levels and tumour size.