This study was undertaken to investigate the effects of acupuncture in low back and pelvic pain during pregnancy under real life conditions, as compared with patients undergoing conventional treatment alone. A total of 61 conventionally treated pregnant women were allocated randomly into two groups to be treated or not by acupuncture. Twenty-seven patients formed the study group and 34 the control group. They reported the severity of pain using a Numerical Rating Scale from 0 to 10, and their capacity to perform general activities, to work, and to walk. We also assessed the use of analgesic drugs. Women were followed up for eight weeks and interviewed five times, at two-week intervals. All women completed the study. In the study group the average pain during the study period showed a larger reduction (4.8 points) than the control group (-0.3 points) (P < 0.0001). Average pain scores decreased by at least 50% over time in 21 (78%) patients in the acupuncture group and in five (15%) patients in the control group (P < 0.0001). Maximum pain and pain at the moment of interview were also less in the acupuncture group compared with the control group. The capacity to perform general activities, to work and to walk was improved significantly more in the study group than in the control group (P < 0.05). The use of paracetamol was lower in the acupuncture group (P < 0.01). These results indicate that acupuncture seems to alleviate low back and pelvic pain during pregnancy, as well as to increase the capacity for some physical activities and to diminish the need for drugs, which is a great advantage during this period.