A series of 51 hysterectomy specimens was studied to define the pathological changes that are present in the area of the post-caesarean section scar. An attempt was made to correlate these findings with the clinical symptoms that had led to the hysterectomy. Scar tissue, present for 2-15 years since the last caesarean section, contributed to significant pathological changes, including distortion and widening of the lower uterine segment (75%), "overhang" of congested endometrium above the scar recess (61%), polyp formation conforming to the contours of the scar recess (16%), moderate to marked lymphocytic infiltration (65%), residual suture material with foreign body giant cell reaction (92%), capillary dilatation (65%), free red blood cells in the endometrial stroma of the scar (suggesting recent hemorrhage) (59%), fragmentation and breakdown of the endometrium of the scar (37%), and iatrogenic adenomyosis confined to the scar (28%). These findings suggest that in some patients the anatomical abnormalities that develop in relation to the scar (especially the presence of a prominent congested fold of endometrium or the presence of small polyps) could give rise to clinical symptoms such as menorrhagia. In addition, inflammatory infiltration with fibrosis and distortion of the lower uterine segment could contribute to such symptoms as lower abdominal pain, dyspareunia, and dysmenorrhea.