Plastic deformation mechanisms in the body centred tetragonal (C16-structure) NiZr2 compound have been studied using transmission electron microscopy. Dislocations, stacking faults and microtwins have been characterized. Four families of dislocations have been identified : screw-type (b = [001]), edge-type ([001](110) and [100](1 (1) over bar 0) systems) and mixed-type (1/2[1 (1) over bar 1](110) system). Partial dilocations associated with stacking faults have also been detected and analysed. The plane of the faults is shown to be (1 (1) over bar 0) and the fault vectors 1/4 [111] and 1/4[11 (1) over bar]. A hard-sphere model illustrating the formation mechan ism of these stacking faults is proposed. The microtwins are found to be 60 degrees rotation twins around the [1 (1) over bar 0]* direction and can be described by the stacking faults scheme.