In order to determine the relative contribution of primary pyroelectricity and secondary pyroelectricity to the total pyroelectric coefficient of polyvinylidene fluoride, samples have been heated suddenly using a 200‐ps laser pulse and the time dependence of the appearance of the pyroelectric charge measured. Charge resulting from primary pyroelectricity would appear as fast as the sample is heated, but charge resulting from secondary pyroelectricity would appear only as rapidly as the sample can relax to the new higher‐temperature dimensions. The results indicate that no significant fraction of the pyroelectricity of polyvinylidene fluoride is primary pyroelectricity. It is suggested that a reversible temperature dependence of the crystallinity might provide an important contribution to pyroelectricity.