Current measurements and serial temperature and salinity observations made in McMurdo Sound during the 1960–61 summer are presented. Most of the current measurements were at two sites close to Cape Armitage, the southern extremity of Ross Island;; these show a residual current of about half a knot flowing towards the Ross Ice Shelf from McMurdo Sound, the fastest currents being close to the sea bottom. Harmonic constants were calculated for the tidal current components.