The invention relates to a device for elastic suspension of an assembly of reservoirs (50, 60) on the underbody of a motor vehicle. The reservoirs (50, 60) are mounted substantially in parallel and have a substantially cylindrical general shape terminated by two shaped end pieces (50A, 50B; 60A, 60B). Said novel suspension device comprises two flanges (10, 11), which fit closely to the shaped end pieces (50A, 50B; 60A, 60B) of the reservoirs (50, 60) and are linked together by tie rods (30) gripping said reservoirs (50, 60), and a plurality of arms (40A, 40B, 40C, 40D) which link the flanges (10, 11) to a plurality of elastic connection points of the suspension device on the vehicle body.