Cycads seeds are ‘same time poison, same time good tucker’ – a nutritionally and culturally significant food on the one hand, but a potentially fatal poison if consumed without sufficient processing. Here, I examine the breakdown of key cycad toxins the azoxyglycosides (AZGs), BMAA and β-sitosterol β-D-glucoside (BSSG) via three cycad processing methods used by Yanyuwa in the southwest Gulf Country, northern Australia. Yanyuwa have long been aware of cycad toxicity and were successfully processing cycad seed long before scientists were aware of their toxicity. This paper aims to present a scientific explanation for the success of Yanyuwa processing methods in relation to the key toxins, in order to build on, and engage, the existing body of Yanyuwa cycad knowledge. In doing so, this paper will address the inclusion of Indigenous knowledge in scientific research and question the perceived need to scientifically validate that which is already known to Indigenous peoples. The study involved discussion with Yanyuwa Elders about cycads as a food source and Yanyuwa preparation methods. Yanyuwa leaching and fermentation processes were replicated under controlled laboratory conditions and the concentration of AZGs (cycasin, macrozamin and neocycasin A), BMAA and BSSG were measured at each stage of processing using LC/MS-MS. I demonstrate that Yanyuwa leaching, fermentation and ageing methods successfully reduced the concentrations of key toxins to within safe ranges, despite significant differences in the concentration of the toxic compounds in unprocessed seed kernels. I argue that the success of Yanyuwa cycad processing is closely tied to cultural practices and social structures, which ensure the consistency and thoroughness of preparation. In closing, I reflect on my own munangangala (western) lens, brought into focus by Yanyuwa Elder Mavis Timothy’s quip – “So what? We already knew this”.