This work characterizes a newly developed, sensitive and convenient spectrophotometric procedure for determination of sub-ppm concentrations of hydrazine and its organic derivatives. The method is based on formation of the cuprous neocuproine chelate after reaction of hydrazines with a prepared aqueous solution of the copper (II)-neocuproine complex. The cuprous chelate is then directly measured in aqueous solution at 458 nm. The effect of several experimental conditions influencing the reaction are presented and the method was employed for the analyis of 5 different hydrazine compounds. The standard deviation did not exceed ± 0.47%.