An instruction compressing apparatus and method for a parallel processing computer such as a very long instruction word (VLIW) computer, are provided. The instruction compressing apparatus includes a bundle code generating unit, an instruction compressing unit, and an instruction converting unit. The bundle code generating unit may generate a bundle code in response to an input of instructions to be compressed. The bundle code may indicate whether a current instruction group is terminated, and also whether an instruction group following the current instruction group is a no-operation (NOP) instruction group. The instruction compressing unit may remove a NOP instruction and/or a NOP instruction group from the input instructions according to the generated bundle code. The instruction converting unit may include the generated bundle code in the remaining instructions which have not been removed by the instruction compressing unit.