Effects of different processing techniques on the neurotoxin, β-ODAP (β-N-oxalyl-L-2,3-diaminopropionic acid), and the anti-nutritional compounds (phytate, polyphenols, trypsin and amylase inhibitors, and lectins) within four lines ofLathyrus sativus(high-, medium- and low-ODAP, and so-called ODAP-free) were investigated. Soaking of seeds in various media reduced the contents of these compounds to a varying and significant extent; losses were higher in freshly boiled water, alkaline and tamarind solutions than after soaking in drinking water. The highest losses in boiled water (65–70%) were observed for β-ODAP, followed by trypsin inhibitors (42–48%) and polyphenols (30–37%). Ordinary cooking and pressure cooking of pre-soaked seeds were found to be most effective in reducing the levels of all the natural toxicants examined, whilst fermentation and germination were more effective in destroying both of the enzyme inhibitors (amylase inhibitors by 69–71%; trypsin inhibitors by 65–66%) than either phytates or polyphenols. Lectins were not affected by most of these processes except by pressure cooking and fermentation. Dehusking of pre-soaked seeds significantly reduced β-ODAP levels, but this reduction was lower for the anti-nutrients. These findings and the high water solubility suggest that a simple and effective means of detoxifyingLathyrusby removing this neurotoxic amino acid may be practicable.