The incidence and character of the bacteremia associated with elective suction abortion was investigated in volunteer subjects aged 19 to 35 years who were to undergo first trimester abortion by suction curettage. One hundred and forty-four blood cultures were obtained from thirteen pregnant and four non-pregnant (control) subjects matched for age. Transient bacteremia occurred during or soon after suction abortion in 11 of 13 (84.7%) study subjects. Four of these patients were bacteremic after bimanual pelvic examination, just prior to initiation of the abortion procedure. Seven others developed bacteremia temporally related to cervical dilatation and suction abortion. The bacteremia was intermittent in some, persistent in others, existed as long as one hour after the procedure, and was transient in all patients. Microorganisms isolated from the blood were all normal genital tract flora and were predominantly anaerobes, although alpha hemolytic streptococci were also recovered. Mixed bacteremia occurred in six patients. In contrast, blood cultures from four non-pregnant women were sterile. This study indicates that the systemic circulation-uterine cavity barrier is significantly disrupted during abortion by suction curettage permitting endogenous genital tract microorganisms to gain access into the bloodstream. These observations also suggest that there may be some risk of developing endocarditis during suction abortion in patients with cardiac deformities, and lend some support to the current practice of giving antibiotic prophylaxis to abortion patients with cardiac lesions which predispose them to endocarditis.