Given the rapid growth in international contacts worldwide, English is increasingly becoming the chosen medium to facilitate communication among people of diverse linguistic and cultural backgrounds. However, the question remains as to how non-native speakers of English of varying levels of proficiency, using different varieties of English, are able to arrive at mutual understanding in this medium. The paper addresses this question by offering some insights into the process of negotiating understanding in English as a lingua franca and the interactional procedures used in this regard. Fifteen hours of transcribed audio recordings of naturally occurring spoken interactions in English as a lingua franca (ELF), between participants of a range of first language and cultural backgrounds, were examined using conversation analytic procedures. Several interactional practices were identified as the ones utilized in the process of constructing shared understanding, namely repetition, paraphrase and various confirmation and clarification procedures. These procedures are strategically employed by both speaker and recipient as warranted by the local context to address problems of understanding when they occur. Thus, regardless of the participants' use of different varieties of English at varying levels of competency, communication is successful as the participants make skilful and adept use of common, shared interactional practices to arrive at mutual understanding.