Abstract: An injection device especially useful in the injection of radio-opaque fluids into humans and animals under continuous pressure includes a pair of blocks mounted side-by-side on a planar base that is supported by legs mounted below the base near its corners. Each block includes a syringe holding passage flanked by a pair of passages shaped to receive rods joined to a weight of predetermined size. The syringe holding passage is narrowed at the bottom to preclude passage of the syringe completely therethrough, but has an opening sufficiently large to permit passage of a needle or a catheter and needle joined to the discharge end of the syringe.A slot extends from the outer surface of each block into the syringe holding passage in that block and extends along the length of the passage and through the base means to permit means joined to the discharge end of the syringe to pass through the block and the base from above the base.