An optimal thickness of the endometrium is considered to be one of the prerequisites for successful implantation of the embryo. A retrospective analysis was carried out to investigate the use of Pentoxyfylline and tocopherol in improving the endometrial thickness in cases that are unresponsive to conventional therapy. Twenty women with thin endometrium (<6 mm) undergoing either ovulation induction or frozen embryo transfer cycles were prescribed 800 mg of PTX and 1000 IU of Vit E daily. In 11 cases, the etiology for thin endometrium was unknown. The known causes included Turners' syndrome (3), Kallman's syndrome (1), idiopathic hypogonadotrophic hypogonadism (2), premature ovarian failure (1) and Asherman's syndrome (2), none of which had responded to conventional hormonal stimulation. The mean duration of treatment was 8.1 months (+/-4.5, range 1-18 months). The mean thickness of endometrium before and after treatment was 4.37 mm (+/-1.5 mm) and 6.05 mm (+/-1.83 mm), respectively (p = 0.001, 95% CI 0.84-2.5). Overall, 14 (73.7%) women showed improvement in endometrial thickness which was the primary outcome. Pregnancy occurred in eight women (40%) of which three were natural, one had ovulation induction and another five had frozen embryo transfers. We conclude that a combination of pentoxyfylline and tocopherol may improve endometrial growth in resistant cases that are unresponsive to conventional therapy.