Most cases of adult GH deficiency (AGHD) result from hypothalamic-pituitary tumors or their treatment. Some experimental and clinical observations suggest that GH may possess a mitogenic potential, thus raising the question of whether it is a safe treatment in patients with a previous pituitary tumor. Few study results have been reported on this topic. All of them have inevitable methodological flaws that limit their conclusions. However, all studies report that replacement therapy with GH does not seem to increase the risk of tumor progression or recurrence, when compared to historical or matched controls. Considering the slow-growing nature of most of these benign tumors and the absence of conclusive evidence from the available studies, a continuous imaging surveillance and longer follow-up periods are nevertheless mandatory for a definite statement on the safety of GH treatment in patients with previous pituitary tumors.