Let Bn be the poset of subsets of {1; 2; : : : ; n} ordered byinclusion and Mn be the poset of monomials in x1; x2; : : : ; xn ordered bydivisibility. Both these posets have an additional linear order making them what is called Macaulayposets. We show in this paper that the pro-les (also called f-vectors) of ideals in Bn and Mn generated bythe -rst elements (relativelyto the linear order) of a given rank are log-concave.