The invention relates to a method in tail threading, in which a lead-in strip, tail (T) separated from the edge of a paper web is guided between two elongated mobile means in a paper web conveying machine and transferred forward between these two means along a given portion in the machine direction of the machine. The mobile means are belts (1, 2) between which the tail is transported. The neutral axes (N) of the belts (1, 2) are substantially on the same level.