Requirements are the heart of Information Systems Development because they determine what the system will operate. Requirements elicitation aims to identify the stakeholders' needs for the Information System. It is a critical and error-prone activity based on an intense communication between several stakeholders with different levels of background that do not always know own needs. Despite many years of research efforts, errors in this activity still occur frequently, cost more if discovered at the implementation stage and are very hard to fix. As a result, these errors represent major causes for the failure of Information Systems. In this work I propose using Focus Groups to obtain high quality requirements that are satisfactory for stakeholders. Focus Groups must engage stakeholders' participation while guiding their discussion towards elicited needs. This proposal was evaluated and refined using Action Research within real world Information System projects. Results allow perceiving lessons learnt and a positive correlation between Focus Groups and the elicitation of high quality requirements. Also, this study contributes in both requirements research and practice.