Any absorption heat pump or heat transformer may be described as the association of two unit operations: the separation of a binary mixture in the desorber/condenser and the mixing of the separated components in the evaporator absorber. Both the separator and the mixer can be constituted of a number of stages. In this paper a multi-stage absorption heat pump for air conditioning will be presented. The objective of this system is to exploit optimally the large temperature difference available for separation (240-35-degrees-C) and the rather small temperature lift for mixing (7-degrees-C-35-degrees-C) and at the same time to maximize the coefficient of performance. The system consists of a N-stage mixer functioning thermally in parallel and materially in series. Examples of multi-stage absorption heat pumps are given using the working fluids ammonia-sodium thiocyanate (NH3-NaSCN) and ammonia lithium nitrate (NH3-LiNO3). The advantages and disadvantages of these types of multi-stage systems are discussed.