A method is presented of measuring the pyroelectric coefficient &lgr; and permittivity &egr; from the initial slope, rise time, and peak value of the pyroelectric response to step radiation signals, valid for temperatures up to the Curie point. An experiment carried out on single‐crystalline triglycine sulphate has yielded the temperature dependence of &lgr; and &egr; with reasonable accuracy and in good agreement with other methods.