This study investigates the effect of local oestrogen therapy (
LET
) on the expression of proteins participating in collagen/elastin biogenesis and immune markers in vaginal tissues of post‐menopausal women with severe pelvic organ prolapse (
POP
). Vaginal biopsies were collected from the anterior vaginal wall of informed and consented 52 post‐menopausal women with severe
POP
undergoing total hysterectomy. Twenty‐nine of the 52 women were treated with
LET
(in the form of vaginal oestrogen cream or tablet), while the remaining 23 untreated patients served as the controls. This study was approved by Sinai Health System
REB
. Vaginal tissue specimens were analysed for gene and protein expression using real‐time
RT
‐
PCR
and Luminex assays, protein localization and immune cell infiltration were assessed by immunohistochemistry. Forty‐four cytokines were detected. We found that
LET
application: (a) significantly increased (
P
< 0.05) gene and protein expression levels of extracellular matrix (
ECM
) structural proteins, collagen and elastin, as well as the expression of
ECM
maturation enzyme
BMP
1
; (b) decreased protein expression level of
ECM
degradation enzymes
MMP
1,
MMP
2 and
MMP
3 accompanied by an increase in their tissue inhibitors,
TIMP
1 and
TIMP
4; (c) significantly increased (
P
< 0.05) the gene and protein expression levels of 14 vaginal cytokines involved in leucocyte infiltration, which was confirmed by immunohistochemistry. Our results indicate that
LET
plays an important role in the activation of immune system within the local vaginal environment, limiting the undesirable
ECM
degradation, which supports the strengthening of vaginal
ECM
in post‐menopausal women, therefore resisting menopause/age‐related changes and inducing urogenital tract tissue regeneration.