An event recorder for use in ethological studies which is of simple and inexpensive construction is described. The apparatus consists essentially of a constant speed paper transport device and an ethogram sheet holder. Up to 20 different behavioral items may be recorded continuously in an accurate time sequence. The items are coded as hand-drawn pencil lines of different length perpendicular to the direction of the paper movement. Since the ethogram code sheets are exchangeable, an unlimited number of different ethograms may be used.