(NH) Bovine Leptospirosis abortion outbreak was diagnosed in a large dairy herd. This herd had experienced an unusually high rate of abortions over a 2-week period of time in cattle that were 6-8 months pregnant. Leptospira were detected by PCR of placenta from 2 abortions. Also, several dams who had aborted had L. Pomona MAT titers of 3200 and 1600. Some breeding bulls on the farm were also tested with the Lepto MAT and several had L. Pomona titers ≥ 12,800. Testing for other causes of infectious bovine abortions were unremarkable.