The thermodynamics of the Ni-Al-B system are assessed based on available literature data. The ternary assessment included the revision of the Al-B binary description to account for the recent experimental work on the melting properties of AlB12. The Ni-Al assessment by Ansara et al. [97 Ansl] and by Huang and Chang [98 Hual] are both considered for the ternary assessment. For the same optimized ternary parameters, the two Ni-Al assessments produced similar results, with the differences increasing at high temperatures near the liquidus.