Saponins are secondary metabolites of plant origin with a steroid or triterpene structure. The combination of a hydrophilic carbohydrate component and a lipophilic aglycone (sapogenin) give them surfactant properties. The absorption of saponins does not increase with excessive peroral use, therefore they are not toxic to the human body or their toxicity is very low. As a result, in recent years they have been the subject of extensive research and studies of their potential use in the pharmaceutical industry, food industry and cosmetics. The saponins possess a wide range of significant pharmacological activities and their use in the therapy of many diseases shows positive results. Their proven in vivo and in vitro antitumor effects, as well as unique immunomodulating and immunostimulating properties, are particularly important. Due to their rich abundance in the plant kingdom, saponis are an easy source for their research and use in the future. In this work, we focused on summarizing the properties, structure, occurrence and utilization of these natural substances. We also describe metabolic pathways leading to the formation of saponins as secondary metabolites in plants and methods for isolating and extracting these substances from plant material.