  After a short review of Q-balls properties, in this paper we discuss their
interaction with matter, and their energy losses in the earth, for a large
range of velocities. These calculations are used to compute the fractional
angular acceptance of a detector located at Gran Sasso Laboratory. Furthermore
we computed the light yield in liquid scintillators, the ionization in streamer
tubes and the Restricted Energy Loss in the CR39 nuclear track detector.
