Royal jelly (RJ) is a natural bee product with great potential for use in medicine. The chemical composition of RJ indicates the presence of various bioactive substances including 10-hydroxydecanoic acid and 24-methylenecholesterol. In addition, a number of biological and pharmacological activities of RJ have been documented. The aim of this study was to review the biological and medical effects of RJ. The search was conducted in articles from electronic and scientific literature databases such as Pub Med, Science Direct, Scopus, Medline, and ISI Web of Science published from 1990 to 2017 using keywords of pharmacological, biological, and clinical effects and royal jelly. Data were chosen after the primary survey of all abstracts and selected full articles. Comparison among related data was done by the authors. Literature has shown that RJ possesses many beneficial effects on biological systems. For example, the therapeutic uses of RJ have been reported in several diseases such as hypercholesterolemia, diabetes, hypertension, and cancers. It was also found to possess neurotrophic, hypotensive, immunomodulatory, antimicrobial, antioxidant, antidiabetic, antihypercholesterolemic, antitumor, and anti-inflammatory effects. Owing to the broad spectrum of biological effects and valuable clinical trials, evaluating the beneficial pharmaceutical effects of RJ in animal and human models seems to be important.