Alternate-layer Langmuir-Blodgett (LB) films containing pendant side-chain polysiloxanes and eicosylamine have been shown to possess an exceptionally high pyroelectric coefficient (similar to 14 mu C m(-2) K-1). This study details the optimisation procedure adopted in order to achieve such high thermal sensitivity. The dependence of the pyroelectric activity on the number of deposited monolayers and cadmium ion content are described. The figure of merit for the best LB pyroelectric sensors prepared in this work is high as 80% of the value of poly(vinylidenedifluoride).