A retrospective study of 400 pregnancies and deliveries was undertaken by interview of 170 consecutive female patients presenting to five chiropractic offices in the Niagara Peninsula. Back pain was reported during 42.5% (170) of the pregnancies and 44.7% (179) of the deliveries. There was a statistically significant association between back pain during the two events (p less than .001). Of the 170 pregnancies with reported back pain, 72% (122) also reported back labor. A subsample of 170 painful pregnancies was divided into those that had received manual manipulation and those that had not. The treated group experienced less pain during labor (p less than .001).