We present the interactions and assembly of triblock cylinders at oilwater and airwater interfaces. ABA-type triblock cylinders with different block ratios and surface wettabilities are prepared using a micromolding method. These triblock cylinders at fluidfluid interfaces induce complex interface deformation depending upon their relative block ratio and the surface wettability. It is observed that triblock cylinders generate octapolar interface deformation at the airwater interface, whereas the same cylinders cause quadrupolar deformation at the oilwater interface. Consequently, the interactions and assembly behavior of these triblock cylinders at each fluid interface strongly depend upon the nature of the interface deformation.