A board design assistance device includes a design data acquirer to acquire design data for a printed circuit board, a first determiner to determine, based on the design data for the printed circuit board, whether a lengthwise direction of board fiber in the printed circuit board is perpendicular to a longitudinal direction of an electronic component mounted on the printed circuit board, a second determiner to determine, based on the design data for the printed circuit board, whether a wire is routed crosswise from a pad receiving the electronic component mounted on the printed circuit board, and a notifier to provide a notification including error information specifying an electronic component determined to have a longitudinal direction not perpendicular to the lengthwise direction of the board fiber and determined to be connected to a pad from which a wire is not routed crosswise.