Forma cristalina de abacavir que está esencialmente libre de disolvente

Forma cristalina de abacavir que está esencialmente libre de disolvente y libre de solvatación de formula (I),**Fórmula** caracterizada por presentar un difractograma de rayos X en polvo que comprende picos característicos a aproximadamente 8,0; 10,0; 10,2; 10,6; 11,9; 12,4, 12,7, 15,0, 16,1, 16,6, 19,5, 20,2, 20,6, 20,7, 21,9, 23,0, 23,9, y 25,0 grados de 2 theta usando una radiación CuKα1 (λ >= 1.54060 Å); y por tener un grado de pureza mayor del 99%. Crystalline form of abacavir that is essentially free of solvent of formula (I), in particular crystalline Form I, and its preparation process which comprises the following steps: a) crystallizing abacavir from a solution of said compound in a (C 1 -C 4 )-alcohol, dichloromethane, acetonitrile/water, or mixtures thereof; b) isolating the crystalline form of abacavir that appears in the prior step; and c) removing the solvent from the crystalline form of abacavir thus obtained. Crystalline Form I can also be obtained by dispersion of abacavir in acetonitrile. The crystalline form of abacavir that is essentially free of solvent is useful for the preparation of pharmaceutical compositions for use in the treatment and/or prophylaxis of HIV infections.