A pedestrian detection system comprising: imaging means for image picking up a front region to generate an image; solid-body recognition means for recognizing a solid body from the image; and pedestrian determination means for determining whether or not the recognized solid body is a pedestrian, further comprising: solid body determination means for determining whether or not a solid body shifts from a first condition in which a first end of the solid body in the horizontal width direction is detected and a second condition in which a second end of the solid body in the horizontal width direction is not detected to a third condition in which the second end is detected, the second condition occurring when only part of the solid body falls within the image, the third condition occurring when the entire solid body in the horizontal width direction appears within the image; and solid body width detection means for detecting the horizontal width of the solid body when the second end is detected; wherein the pedestrian determination means is adapted to determine whether or not the solid body is a pedestrian by comparing the horizontal width of the solid body with a preset threshold value, and wherein the solid body determination means is adapted to compare the distance from the pedestrian to a determination range and, when the pedestrian is present within the determination range, determine that there is a risk of collision. imaging means for image picking up a front region to generate an image; solid-body recognition means for recognizing a solid body from the image; and pedestrian determination means for determining whether or not the recognized solid body is a pedestrian, further comprising: solid body determination means for determining whether or not a solid body shifts from a first condition in which a first end of the solid body in the horizontal width direction is detected and a second condition in which a second end of the solid body in the horizontal width direction is not detected to a third condition in which the second end is detected, the second condition occurring when only part of the solid body falls within the image, the third condition occurring when the entire solid body in the horizontal width direction appears within the image; and solid body width detection means for detecting the horizontal width of the solid body when the second end is detected; wherein the pedestrian determination means is adapted to determine whether or not the solid body is a pedestrian by comparing the horizontal width of the solid body with a preset threshold value, and wherein the solid body determination means is adapted to compare the distance from the pedestrian to a determination range and, when the pedestrian is present within the determination range, determine that there is a risk of collision. solid body determination means for determining whether or not a solid body shifts from a first condition in which a first end of the solid body in the horizontal width direction is detected and a second condition in which a second end of the solid body in the horizontal width direction is not detected to a third condition in which the second end is detected, the second condition occurring when only part of the solid body falls within the image, the third condition occurring when the entire solid body in the horizontal width direction appears within the image; and solid body width detection means for detecting the horizontal width of the solid body when the second end is detected; wherein the pedestrian determination means is adapted to determine whether or not the solid body is a pedestrian by comparing the horizontal width of the solid body with a preset threshold value, and wherein the solid body determination means is adapted to compare the distance from the pedestrian to a determination range and, when the pedestrian is present within the determination range, determine that there is a risk of collision.