Objective. To evaluate the efficiency of treatment in patients with the hypoplastic type of chronic endometritis (CE) by uterine cavity irrigation with cavitation drug solutions exposed to low-frequency ultrasound (LFUS). Subjects and methods. 128 women diagnosed with the hypoplastic type of CE were examined. hypoplastic option. 64 patients of a study group (Group 1) received drug therapy and irrigation with a 0.05% cavitation chlorhexidine solution exposed to LFUS and with an immunomodulator solution (a total of 3 cycles). 64 patients of a comparison group (Group 2) had drug therapy only. The results were assessed by the time course of changes in the size of M-echo, endometrial histological examination before and after treatment, the occurrence of pregnancy and its outcomes. Results. The pretreatment endometrial thickness (M-echo data) was 5.8 ± 0.8 mm in Group 1 and 5.8 ± 0.5 mm in Group 2 (p = 0.899), the posttreatment one was 8.6 ± 0.3 and 6.4 ± 0.9 mm, respectively (p = 0.000). In the patients of the study group, the histological pattern in the endometrial biopsy specimens was observed to normalize in 11 (17.2 ± 0.05) and 64 (100%) patients after cycle treatments 2 and 3, respectively. In the comparison group, the endometrium after 4 and 6 months of treatment corresponded to the phase of the cycle in 2 (3.1% ± 0.02) and 18 (28.1% ± 0.06) women, respectively. In the first year after the end of therapy, pregnancy occurred substantially more commonly in Group 1 than in the comparison group (45.3 versus 28.15%). Pregnancy ended in childbirth in 89.7% of the patients in Group 1 and in 44.4% in Group 2; in these groups, there were miscarriages in 10.3 and 55.6%, respectively. Conclusion. Thus, LFUS used in patients with the hypoplastic type of CE promotes the adequate growth of the endometrium and the creation of favorable conditions for ovum implantation. © Bionika Media Ltd.