Mixing of gaseous species using jets in cross-flow is investigated with the help of computational fluid dynamics (CFD) modeling. This situation is encountered in a variety of industrial situations such as combustion, chemical vapor deposition, etc. Such operations are carried out in a specially designed chamber/mixer. For example, hydrocarbons are mixed with oxygen prior to oxidation reactions, in a specially designed oxygen mixer. In the present work, CFD simulations have been carried out for the mixing of two gaseous streams in a mixer. The model has been validated with experimental data reported in the past literature. The effects of different geometric configurations (hole diameter, number of holes) and operating conditions (velocity ratio) oil the mixing process have been investigated. The model has helped in the identification of the key parameters in the design of such mixers.