A vehicle surroundings monitoring device for producing a synthesized image showing the situation around a vehicle from images taken with a stereoscopic camera system comprising at least one camera (11a, 11b) capturing the surroundings of the vehicle and presenting the synthesized image at a display unit, the device comprising: a position computation section configured to select corresponding points of at least two camera images and to compute three dimensional coordinates for a plurality of points based on the two dimensional image coordinates of the corresponding points and further configured to compute a reliability of the three dimensional coordinates, for each of the plurality of points by inversely computing two dimensional image coordinates from the three dimensional coordinates by the method of least squares and comparing the inversely computed two dimensional image coordinates with the two dimensional image coordinates;; an image variable-synthesis section configured to produce a first synthesized image based on the images taken with the at least one camera (11a, 11b) and the three dimensional coordinates and the corresponding image coordinates and having a predetermined viewpoint which is different from a viewpoint of the at least one camera; an image fixed-synthesis section configured to produce a second synthesized image, based on the images taken with the at least one camera (11 a, 11 b) by a predetermined method using the plane of road surface as the reference together with a reference table and without use of the three dimensional coordinates and the corresponding image coordinates and further having a predetermined viewpoint which is different from a viewpoint of the at least one camera, characterized by a synthesis scheme selection section (17, 17A) configured to select either the first synthesized image or the second synthesized image based on the average value of the single reliabilities of the plurality of points in the images as the synthesized image to be presented at the display unit. a position computation section configured to select corresponding points of at least two camera images and to compute three dimensional coordinates for a plurality of points based on the two dimensional image coordinates of the corresponding points and further configured to compute a reliability of the three dimensional coordinates, for each of the plurality of points by inversely computing two dimensional image coordinates from the three dimensional coordinates by the method of least squares and comparing the inversely computed two dimensional image coordinates with the two dimensional image coordinates;; an image variable-synthesis section configured to produce a first synthesized image based on the images taken with the at least one camera (11a, 11b) and the three dimensional coordinates and the corresponding image coordinates and having a predetermined viewpoint which is different from a viewpoint of the at least one camera; an image fixed-synthesis section configured to produce a second synthesized image, based on the images taken with the at least one camera (11 a, 11 b) by a predetermined method using the plane of road surface as the reference together with a reference table and without use of the three dimensional coordinates and the corresponding image coordinates and further having a predetermined viewpoint which is different from a viewpoint of the at least one camera, characterized by a synthesis scheme selection section (17, 17A) configured to select either the first synthesized image or the second synthesized image based on the average value of the single reliabilities of the plurality of points in the images as the synthesized image to be presented at the display unit.