An image reading device includes a first reading unit, second reading unit, and determining unit. The first and second reading units are configured to read one surface and another surface of an original, respectively. The second reading unit is disposed downstream of the first reading unit with respect to a conveying path. The determining unit determines, based on read data obtained by reading the one surface with the first reading unit before the original is arrived at the second reading unit, whether or not an image is formed on the one surface. The first reading unit continues reading the one surface and the second reading unit fails to read another surface when an image is formed on the one surface. The second reading unit reads another surface and the first reading unit fails to read the one surface when an image is not formed on the one surface.