Details are presented of the H I Jodrell All Sky Survey (HIJASS). HIJASS is a blind neutral hydrogen (H I) survey of the northern sky ({delta}>22{deg}), being conducted using the multibeam receiver on the Lovell Telescope (full width at half-maximum beamwidth 12-arcmin) at Jodrell Bank. HIJASS covers the velocity range -3500 to 10000 km/s, with a velocity resolution of 18.1km/s and spatial positional accuracy of ~2.5arcmin. Thus far about 1115 deg2 of sky have been surveyed. The average rms noise during the early part of the survey was around 16mJy/beam Following the first phase of the Lovell Telescope upgrade (in 2001), the rms noise is now around 13mJy/beam. We describe the methods of detecting galaxies within the HIJASS data and of measuring their H I parameters. The properties of the resulting H I-selected sample of galaxies are described. Of the 222 sources so far confirmed, 170 (77 per cent) are clearly associated with a previously catalogued galaxy. A further 23 sources (10 per cent) lie close (within 6 arcmin) to a previously catalogued galaxy for which no previous redshift exists. A further 29 sources (13 per cent) do not appear to be associated with any previously catalogued galaxy. (1 data file).