At present time, cell phone is a device found almost everywhere and in every situations of the people s life as a condition known as Ubiquitous Technology. In 2003, the total cell phone users overcame the total fixed line users in Brazil. The frequently cell phone changes with different systems and without user centered studies increase the cell phone use difficulties. An aspect more evident is with one of most used function, the phonebook. Many authors describe the need of guidelines to help the quality of this Human Computer Interaction. This research applied qualitative and quantitative techniques to verify the relation between cell phone usability and application of usability ergonomic criteria. The techniques applied were Interviews, Focus Group, Cooperative Evaluations and Questionnaires. These techniques were developed with focus on cell phones phonebook use.