Neutropenic sepsis is a medical emergency and complication of cancer treatment, usually chemotherapy.

It is thought to be brought about through a combination of the effect of chemotherapy in supressing the bone marrow, and in turn the production of white blood cells, as well as the breakdown of the lining of the gastrointestinal tract, allowing for bacteria to enter the blood stream.

It is a medical emergency, and patients with suspected neutropenic sepsis should receive broad spectrum, empirical antibiotics no later than 1 hour after arriving at hospital.