We present HI observations of the galaxies in the first list of the Karachentsev catalog of previously unknown nearby dwarf galaxies ( Karachentseva & Karachentsev 1998 ) . This survey covers all known nearby galaxy groups within the Local Volume ( i.e . within 10 Mpc ) and their environment , that is about 25 % of the total sky . A total of 257 galaxies have been observed with a detection rate of 60 % . We searched a frequency band corresponding to heliocentric radial velocities from -470 km s ^ { -1 } to \sim +4000 km s ^ { -1 } . Non-detections are either due to limited coverage in radial velocity , confusion with Local HI ( mainly in the velocity range -140 km s ^ { -1 } to +20 km s ^ { -1 } ) , or lack of sensitivity for very weak emission . 25 % of the detected galaxies are located within the Local Volume . Those galaxies are dwarf galaxies judged by their optical linear diameter ( 1.4 \pm 0.2 kpc on the average ) , their mean total HI mass ( 4.6 10 ^ { 7 } M _ { \odot } ) , and their observed linewidths ( 39 km s ^ { -1 } ) .