Abstract: In a method and arrangement for reducing dust-related problems in rock drilling, air and liquid mist is supplied into a drilling hole to moisten the dust that comes off the drilling hole. The air and moistened dust exiting from the drilling hole are led to a dust separator, dust portions that collect into the dust separator being removed therefrom at suitable intervals. When dust is to be removed from the dust separator's filter, liquid is supplied to the portion below the filter in a mist-like form or as small droplets in connection with the dust removal to moisten the dust which then falls out of the lower end of the dust separator.