The previously published low temperature heat capacity data of four ZrZn2 samples were analyzed to extract the magnetic entrop, Sm(T). The well‐ordered vapor deposited ZrZn2 with Tc?22 K showed a finite but small Sm(T) of 110 mJ/gm mole K, indicating that it very much an itinerant electron ferromagnet. However the dramatic increase of Sm(T) with the increase of Curie temperature suggests that better the samples more the deviation from the Stoner‐Wohlfarth band theory. The magnetic measurements, carried out on the same samples confirm the general applicability of the band theory and the sensivity of the samples to the details of preparation and heat treatment.