Some characteristics of the subsurface temperature structure in the north Tasman Sea as measured by expendable bathythermograph probes are discussed, Vertical sections of temperature generally show a subsurface thermal front which appears to meander north‐eastward from an area shallower than 1000 m and centred on 33°S, 162° 30 E on the Lord Howe Rise to an area on the Norfolk Ridge near 32° S, 167° 30 E where the depth is less than 500 m; the warmer water lies north‐west of the front. This front, which is given the name “Tasman Front”, probably results from the flow of the East Australian Current as a zonal jet across the north Tasman Sea from the east coast of Australia to the north of New Zealand.