The Ghaychak [qeicak] (or Ghajak [qajak]) is a bowed fiddle of the Persian folk music particularly played in the southeastern region of Iran.

There are two large holes on the upper side near the fingerboard and one on the lower tip which is covered with a skin membrane. There are four main strings and eight to sixteen sympathetic strings which have been eliminated in the context of Traditional Persian Music.

The sound box resembles an upside-down anchor which is carved from a tree trunk and is placed vertically on the player's lap. The upper and lower sections are separated by two oval indentations on the right and left side which give the ghaychak a distinct nasal sound.