We measure and analyze the sizes of 82 massive (M ≥ 1011 M &sun;) galaxies at 1. 7 ≤ z ≤ 3 utilizing deep HST NICMOS data taken in the GOODS North and South fields. Our sample provides the first statistical study of massive galaxy sizes at z > 2. We split our sample into disk-like (Sérsic index n ≤ 2) and spheroid-like (Sérsic index n > 2) galaxies, and find that at a given stellar mass, disk-like galaxies at z ˜ 2. 3 are a factor of 2. 6 ± 0. 3 smaller than present day equal mass systems, and spheroid-like galaxies at the same redshift are 4. 3 ± 0. 7 times smaller than comparatively massive elliptical galaxies today. We furthermore show that the stellar mass densities of very massive galaxies at z ˜ 2. 5 are similar to present-day globular clusters with values ˜ 2 ×1010 M&sun; kpc - 3.