This paper attempts to present a Critical Discourse Analysis (CDA) of Nelson Mandela's defense speech "I am prepared to die," which was delivered in 1964 during his trial in what is often called as Rivonia Trial. More specifically, the paper tries to explore the hidden relations of power and ideologies that have been encoded in Mandela's defense speech. The main research question is: what are the ideological meanings Mandela tries to communicate through his speech, and how are these ideologies conveyed by CDA strategies? The paper draws on Critical Discourse Analysis (CDA), as discussed in the writings of Fairclough (1989, 2013) and Van Dijk (1993, 2001, 2014). The analysis covers two levels of analysis: the lexical level and the pragmatic level of analysis. Both levels are discussed under the theoretical umbrella of CDA. The paper reveals that Mandela managed, by using specific CDA strategies, to communicate particular ideological meanings that reflect his political stance, as well as his rebellious spirit as the most distinguished revolutionary leader who struggles against racial discrimination in South Africa.