The paper presents experimental and processed data of gas permeation through stretched polyisoprene rubber membranes. As a consequence of the membrane stretching, the polymer chains flexibility decreases and the penetrant path length increases. Gas diffusion, solubility and permeability coefficients depend on stretching intensity. Two methods were used to estimate the permeability coefficients of pure gases, i.e. hydrogen, oxygen, nitrogen, methane and carbon dioxide. A dynamic method was based on volume and pressure measurements of rubber balloons filled with gas. A time-lag method was employed to study the gas permeation through rubber membranes placed in a permeation cell. Both methods gave comparable results. (C) 2011 Elsevier B.V. All rights reserved.