Abnormal serum human chorionic gonadotropin (hCG) levels during the first trimester may be associated with a nonviable intrauterine pregnancy or ectopic pregnancy. With the availability of sensitive hCG assays, expectant management of these patients may provide a viable alternative to surgery. To evaluate this approach, we managed 20 patients with low levels of serum hCG expectantly using serial hCG monitoring and clinical examination only. Serum hCG concentrations were followed to levels of < 10 mlU/ml. Peak levels of serum hCG ranged from 72 to 5,685 mlU/ml. Duration of expectant management ranged from 7 to 97 days. No patient required intervention due to acute symptoms. These data suggest that a select group of patients with decreasing hCG concentrations may be managed expectantly without undue morbidity therby avoiding surgical intervention.