Mobile and wireless devices and networks enable "any place, any time" use of information systems, providing advantages, such as productivity enhancement, flexibility, service improvements and information accuracy. These benefits can be nullified by using systems of insufficient quality. Mobile-wireless information systems face new kinds of problems: narrow bands, small devices, tiny screens, and diversity of users and devices. Information systems quality cannot be measured only by software faults absence; it must be broader, including characteristics to cover all aspects, life-cycle phases, and viewpoints. This research develops a methodology to define and quantify the quality components of such systems, merging two fields together: mobile-wireless applications and standards for product quality assurance. The research has developed a list of questions from which new quality metrics were defined and empirically validated, extending the ISO/IEC 9126 quality standard for mobile-wireless information systems. The paper describes the metrics development process and presents examples of metrics.