We present new 21-cm neutral hydrogen (H I) observations of spiral galaxies for the 2MASS Tully-Fisher (2MTF) survey. Using the 64-m Parkes radio telescope multibeam system we obtain 152 high signal-to-noise ratio H I spectra from which we extract 148 high-accuracy (<5 per cent error) velocity widths and derive reliable rotation velocities. The observed sample consists of 303 southern (δ < -40°) galaxies selected from the 2MASS Redshift Survey with Ks < 11.25 mag, cz<10 000 km s-1 and axis ratio b/a<0.5. The H I observations reported in this paper will be combined with new H I spectra from the Green Bank and Arecibo telescopes, together producing the most uniform Tully-Fisher survey ever constructed (in terms of sky coverage). In particular, due to its near-infrared selection, 2MTF will be significantly more complete at low Galactic latitude (|b| < 15° and will provide a more reliable map of peculiar velocities in the local Universe.