The stress-strain behaviour of metals under a cyclic loading is very miscellaneous and needs an individual approach for different metallic materials. There are many different models that have been developed for the case of cyclic plasticity. This chapter will address only so called phenomenological models, which are based purely on the observed behaviour of materials. The second section of this chapter describes the main experimental observations of cyclic plasticity for metals. Material models development for the correct description of particular phenomenon of cyclic plasticity is complicated by such effects as cyclic hardening/softening and cyclic creep (also called ratcheting). Effect of cyclic hardening/softening corresponds to hardening or softening of material response, more accurately to decreasing/increasing resistance to deformation of material subjected to cyclic loading. Some materials show very strong cyclic softening/hardening (stainless steels, copper, etc.), others less pronounced (medium carbon steels). The material can show cyclic hardening/softening behaviour during force controlled or strain controlled loading. On the contrary, the cyclic creep phenomenon can arise only under force controlled loading. The cyclic creep can be defined as accumulation of any plastic strain component with increasing number of cycles and can influence the fatigue life of mechanical parts due to the exhaustion of plastic ability of material earlier than the initiation of fatigue crack caused by low-cycle fatigue is started.