"Cetiosauriscus" was originally classified by Huene as a genus in the family Cetiosauridae, within the subfamily Cardiodontidae. The subfamily, including the other taxa "Cetiosaurus", "Haplocanthosaurus", "Dystrophaeus", "Elosaurus" and "Rhoetosaurus", was founded upon the general basal features of elongate cervicals and shortened dorsals—both opisthocoelous, caudals that are rod-shaped distally, paired sternal plates, an ilium lacking the postacetabular process (region of the ilium behind the ischium joint and acetabulum), a very wide pubis, wide distal ischium, significantly shorter forelimb than hindlimb, fibula lacking the middle muscle attachment, and long metacarpals and short metatarsals. This classification was emmended in 1932 when Huene concluded "Cetiosauriscus" was closer to "Haplocanthosaurus" than "Cetiosaurus" in the family, because of forelimb and hindlimb proportions. Conversely, in 1956, Alfred Romer synonymised "Cetiosauriscus" and "Cetiosaurus", a position that has not been followed by subsequent studies on the taxon.