Evidence based practice (EBP) is a three-pillared approach whereby information on the research evidence, factors relating to the patient and clinical experience are all considered to inform a care decision. Unfortunately, there is frequently very little research evidence to inform speech and language therapy interventions. To better inform speech and language therapy practice, the authors of this article argue that the EBP model requires extending - specifically when considering the areas of patient-related factors and practice-based knowledge (or clinical experience). They suggest that research evidence is not as important as practice-based knowledge and patient experience, within speech and language therapy. With this in mind the authors have proposed an alternative model: A Total Evidence and Knowledge Approach (TEKA) comprising intervention description; alternative treatment options; research evidence; practice evidence; patient evidence and contextual evidence. They propose that by using this much broader analysis, clinicians will be better able to make decisions about, and understand the rationale for delivering interventions. Using a TEKA model to inform every clinical decision may be unrealistic but understanding the principles of the TEKA model and exploring these to expand our critical thinking will be of significant benefit to speech and language therapy.