Black carbon (BC) concentration was measured from 211 ship exhaust gas plumes at a remote marine station. Emission factors of BC were calculated in grams per kilogram of fuel. Ships with an exhaust gas cleaning system (EGCS) were found to have median BC emissions per fuel consumed 5 times lower than ships without an EGCS. However, this might be because of non-EGCS ships running at low engine loads rather than the EGCS itself. A local speed restriction would increase BC emissions of ships.