Recent studies suggested thatEurycoma longifolia, a herbal plant, may have the potential to treat osteoporosis in elderly male. This study aimed to determine the effects ofEurycoma longifoliasupplementation on the trabecular bone microarchitecture of orchidectomised rats (androgen-deficient osteoporosis model). Forty-eight-aged (10–12 months old)Sprague Dawleyrats were divided into six groups of sham-operated (SHAM), orchidectomised control (ORX), orchidectomised + 7 mg/rat testosterone enanthate (TEN) and orchidectomised +Eurycoma longifolia30 mg/kg (EL30), orchidectomised +Eurycoma longifolia60 mg/kg (EL60), orchidectomised +Eurycoma longifolia90 mg/kg (EL90). Rats were euthanized following six weeks of treatment. The left femora were used to measure the trabecular bone microarchitecture using micro-CT. Orchidectomy significantly decreased connectivity density, trabecular bone volume, and trabecular number compared to the SHAM group. Testosterone replacement reversed all the orchidectomy-induced changes in the micro-CT parameters. EL at 30 and 60 mg/kg rat worsened the trabecular bone connectivity density and trabecular separation parameters of orchidectomised rats. EL at 90 mg/kg rat preserved the bone volume. High dose of EL (90 mg/kg) may have potential in preserving the bone microarchitecture of orchidectomised rats, but lower doses may further worsen the osteoporotic changes.