Mast cells are well known as the producers of histamine and major effectors of type 1 hypersensitivity. They play however an important role in many other physiological and pathological processes. Lesser-known is their role in the processes such as a termination of pregnancy and initiation of delivery. The mast cells are considered as the modulators of endocrine signals on the local reactions in uterus. Many substances produced by the mast cells have the angiogenic effects known primarily for their role in tumour growth, but they influence also embryonal and postnatal growth or process of wound healing. Mast cells also participate in a number of compensatory reactions in the tissue response to the mechanical load, hypoxia or inflammation (airway remodelling in asthma, remodelling of pulmonary vessels in chronic hypoxia, myocardial hypertrophy, liver cirrhosis, chronic pancreatitis). This review describes recent concepts of their role in labour, non-cancerous angiogenesis and remodelling of pulmonary vasculature during chronic hypoxia.