Introduction Guidelines for cross‐sex hormone treatment of transsexual people are now in place. However, little attention has been paid to the issue of treatment suitability for older people. Does existing treatment need to be adapted as subjects age, and does it make a difference if treatment is only started when the subject is already older?

Aim To assess the necessity of adapting cross‐sex hormone administration for elderly transsexual people.

Main Outcome Measures Risks/benefits of continued use of cross‐sex hormones with regard to bone health, cardiovascular risks, and malignancies.

Methods Due to lack of data on the subject population, sex hormone treatment of other conditions in older non‐transsexual people has been taken as the best available analogy to determine the extent to which these might be applicable to comparable transsexual persons. Findings in transsexual people receiving cross‐sex hormone treatment sometimes modified the above approach of applying guidelines for the elderly to the aging transsexual population.

Results Testosterone administration to female‐to‐male transsexual persons (FtoM) carries little risk with regard to cardiovascular disease and cancer. For those with high hematocrit or cardiac insufficiency the dose can be reduced. Administration of estrogens to male‐to‐female transsexual persons (MtoF), particularly when combined with progestins, does significantly increase the risk of developing cardiovascular disease (almost a twofold incidence compared with the general population). This may require dose adjustment or changing from oral to safer transdermal estrogens. Tumors of the breasts, prostate and pituitary may occur. In FtoM, breast cancer can occur even after breast ablation. Older subjects can commence cross‐sex hormone treatment without disproportionate risks.