Taraxacum officinale or dandelion (Asteraceae or Compositae family), is an edible plant spread worldwide. It has been believed that dandelion originated in Greece, or perhaps the Northern Himalayas, and spread across temperate areas to Europe and Asia Minor. Dandelion is widely used worldwide in food products. It is traditionally proposed as a dietary supplement and herbal remedy for the prevention, management, and treatment of various human diseases. This review intended to investigate the pharmacological and therapeutic features of dandelion in traditional medicine and scientific documents. Results from several studies indicated that this plant owned numerous biological potencies, including anti-inflammatory, anti-tumor, immunostimulatory, anti-microbial, anti-viral, anti-oxidant, anti-diabetic, geno-protective, diuretic and kidney-protective, hepato-protective, neuro-protective, anti-depressant, lung-protective, pancreas-protective, and differentiation-inducing actions as well as exerting a positive influence on dyslipidemia, hematological profile, stomach motility, fatigue, and bifidobacteria. Nevertheless, the exact mechanism of action for these features is not fully understood. All the studies done on dandelion involved experimental animal studies as well as some human studies and cell cultures, and no clinical data are available for the claimed benefits in the prevention and treatment/management of diseases. Available published data about animal and human studies, both in vitro and in vivo showed great potentials for the use of dandelion as therapy in most diseases. For such a ubiquitous herb, well-designed human studies are surprisingly rare. Due to the lack of toxicity and side effects, this plant has been considered as a worthwhile complementary drug. Further clinical trials are required to validate the reported promising experimental effects in clinical use. Here we reviewed the studies that validated the efficacy of dandelion claimed by traditional healers.