The pulmonary drug delivery system offers several merits over other drug delivery systems and therefore, this delivery route has been in prime focus for various applications like local and systemic therapeutics delivery. The overall development of drug delivery system depends on its efficacy, quality and safety and to achieve such attributes there is a need of reliable evaluation methods to test them. This review provides an in-depth analysis of the development in the evaluation of pulmonary drug delivery systems. In vitro methods of testing pulmonary products such as particle morphological studies, powder flow characteristics, moisture content test, aerosol turboelectric characterization, particles interparticulate forces measurement and solid state characterizations were discussed. Particle size and zeta potential measurement and evaluation of aerosol performance such as dose uniformity and aerodynamic particle size distribution were reviewed in detail. The development of dissolution methods for pulmonary products is also elaborated. Various cell culture methods for testing pulmonary products were overviewed. The in vivo testing methods including drug administration systems, drug deposition studies and pharmacokinetic studies and ex vivo testing models were also highlighted. Together an overview of current advancement in evaluation and characterization of pulmonary drug delivery system can be analyzed and studied through this review.The pulmonary drug delivery system offers several merits over other drug delivery systems and therefore, this delivery route has been in prime focus for various applications like local and systemic therapeutics delivery. The overall development of drug delivery system depends on its efficacy, quality and safety and to achieve such attributes there is a need of reliable evaluation methods to test them. This review provides an in-depth analysis of the development in the evaluation of pulmonary drug delivery systems. In vitro methods of testing pulmonary products such as particle morphological studies, powder flow characteristics, moisture content test, aerosol turboelectric characterization, particles interparticulate forces measurement and solid state characterizations were discussed. Particle size and zeta potential measurement and evaluation of aerosol performance such as dose uniformity and aerodynamic particle size distribution were reviewed in detail. The development of dissolution methods for pulmonary products is also elaborated. Various cell culture methods for testing pulmonary products were overviewed. The in vivo testing methods including drug administration systems, drug deposition studies and pharmacokinetic studies and ex vivo testing models were also highlighted. Together an overview of current advancement in evaluation and characterization of pulmonary drug delivery system can be analyzed and studied through this review.