Water extracts (infusions) from a group of medicinal plants were studied in terms of their activity enhancing the uterine tonus in a series of experiments with a preparation of an isolated rabbit and guinea pig uterine horn. In a final extract concentration of 1 to 2 mg crude drug per 1 cm3 the plants ranked in the following descending order with regard to their tonus-raising effect on the uterus: camomile (Matricaria chamomilla L.), potmarigold calendula (Calendula officinalis L.) cockscomb (Celosia cristata L.), plantain (Plantago lanceolata L. et Plantago major L.), symphytum (Symphytum officinale L.), shepherdspurse (Capsella bursa pastoris L.), St.-John's wort (Hypericum perforatum L.). No effect showed the infusions of flax seeds (Linum usitatissimum L.) and bearberry leaves (Arctostaphylos uva-ursi L.). The combined preparation 'Antiinflamin', consisting of a pooled freeze-dried extract from three plants and chemotherapeutic agents produced a good enhancing effect, in the form of 'comprets' for intrauterine application at the rate of one compret per 2500 cm3.