Thymus serpyllum L. (wild thyme) is a perennial shrub, native to areas of northern and central Europe. Its aerial parts are most frequently used in ethnomedicine (mainly for treating illnesses and problems related to the respiratory and gastrointestinal systems), although recently its essential oils are becoming more popular as an important plant-derived product. The composition of these oils is affected by geographic region, the development stage of the plant, the harvest season, habitat, and climatic conditions. Wild thyme essential oil has an ever-growing number of uses in contemporary medicine due to its pharmacological properties: antioxidative, antimicrobial, and anticancerogenic activities. The antioxidative and antimicrobial properties of the essential oil are related to the synergistic and cumulative effect of its components. In terms of antitumor and cytotoxic activity, further research into the effects of essential oil is necessary, aimed at improving its cytotoxic effects, on the basis of which appropriate medicines can be formulated. Due to its pharmacological properties, the essential oil of wild thyme, a plant used in traditional medicine, represents an important natural resource for the pharmaceutical industry. In addition, it can be a source of natural antioxidants, nutritional supplements, or components of functional foods in the food industry.