Oilseed plants are a valuable group of foods in human nutrition. Uncommon oilseed plants, such as safflower (Carthamus tinctorius L.), camelina (Camelina sativa L.), and black cumin (Nigella sativa L.), have been gaining increasing attention. The unique chemical compositions of these plants, which contribute to potential health benefits, underscore the importance of further exploration and study. The continuation of development of research in this field, resulting in the well-documented positive impact of these plants on human health, may lead to the possibility of them becoming new functional foods in the future. This review aims to present the potential health-promoting properties of the aforementioned uncommon oilseed plants based on recent literature reports and intends to inspire further exploration of their unique features. Among others, recent reports on the anticancer, antioxidant, and antibacterial potential, as well as the preventive potential in the case of metabolic diseases of these plants, were discussed. The importance of further development of these problems was also emphasized.