The first criticism of Avicenna in Averroes's Long Commentary on Metaphysica (II, 993a30-995a20) regards Avicenna's doctrine of the asexual (so-called 'spontaneous") generation of human beings. This criticism is interesting in two main regards. When considered in the general historical context of the confrontation between advocates and opponents of spontaneous generation, the specific debate between Averroes and Avicenna on this issue can be said to have had a long-lasting impact on Latin philosophy up until the Renaissance. Doctrinally, the criticism in question can be taken as a paradigm of Averroes's more general anti-Avicennian polemic and of the ideological reasons of his dissent towards his illustrious predecessor. In fact, the criticism in questions displays three leitmotivs of Averroes's dissent towards Avicenna: the harsh tone and the ad personam character of the attack, stressing an error unworthy of Avicenna's alleged fame in philosophy; the insistence on Avicenna's agreement and consonance with contemporary thinkers, a fact that in Averroes's eyes evidences the profound gap separating Avicenna from the ancient masters, depositaries of authentic philosophy; the reproach addressed to Avicenna of being too conversant with, and receptive of, Islamic theology, thus disregarding the requirements of true philosophy. The article shows that in each of these three respects Averroes in fact presents Avicenna's position in a biased way: indeed Avicenna does not uphold the specific version of human spontaneous generation that Averroes ascribes to him; his doctrine of human spontaneous generation is deeply rooted in ancient philosophy; and his account of this doctrine evidences clear non-religious (and therefore non-theological) traits.