Development of decidedly sensitive and selective gas sensors is desirable to maintain control of environment quality against hazardous pollutant. The adsorption of H 2 S and SO 2 molecules on pristine and Zn doped MoSe 2 structures is examined by first principles computations - density functional theory (DFT). The work involves analysis of adsorption energy and distance, charge transferred between a structure and a gas molecule, band structure, and density of states (DOS). The band structure of MoSe 2 reveals substantial variations of its electronic properties upon doping with Zn. Furthermore, new bands have been developed near the Fermi level within the DOS due to Zn doping of MoSe 2 structure. The adsorption of both H 2 S and SO 2 gases on Zn–MoSe 2 structure is greatly enhanced, as compared with the pristine structure. The Zn-modified MoSe 2 structure exhibits larger adsorption energy for H 2 S gas, hence, better sensitivity is comparison with SO 2 gas. This work illustrates that Zn doping of MoSe 2 structure may be considered for sensitive detection of H 2 S gas. • Zn doped MoSe 2 was explored for sensors applications of H 2 S and SO 2 gases using DFT calculation. • The gas adsorption capacity was investigated using: adsorption energy and distance, charge transferred, and DOS. • Excellent improvement was observed for H 2 S and SO 2 adsorption after doping. • Adsorption energy for H 2 S gas of Zn-MoSe 2 structure was 5.5 times more than that of the pristine structure. • Adsorption energy for SO 2 gas of Zn-MoSe 2 structure was 3 times more than that of the pristine structure.