Recent studies have sought to understand individuals' motivations for terrorism through terrorist material content. To date, these studies have not capitalised on automated language analysis techniques, particularly those of corpus linguistics. This paper demonstrates how applying three corpus-linguistic techniques to extremist statements can provide insights into their ideology. The data consist of 250 statements (approximately 500,000 words) promoting terrorist violence. Using the online software tool Wmatrix, the paper submitted these data to frequency count, key word and key concept, and concordance analyses. Results showed that authors centre their rhetoric on themes of morality, social proof, inspiration and appeals to religion, and refer to the world via contrasting concepts, suggesting a polarised way of thinking compared to a general population usage. Additionally, it is shown how collocation can aid the establishment of networks between people and places. It is discussed how such analyses might support the formulation of evidence based counter-terrorism strategies.