Purpose – This study explains blockchain adoption in financial institutions through a mechanism-based integration of the technology–organization–environment (TOE) framework and the technology acceptance model (TAM). It examines how technological, organizational and environmental conditions are translated into blockchain adoption through cognitive evaluations of perceived ease of use and perceived usefulness. Design/methodology/approach – A quantitative design was employed using survey data from 479 employees in financial institutions. The proposed model was tested through structural equation modeling (SEM), enabling the examination of direct, indirect and sequential mediation effects among TOE dimensions, perceived ease of use, perceived usefulness and blockchain adoption. Findings – Blockchain adoption is explained primarily by perceived usefulness, while perceived ease of use influences adoption directly and indirectly through usefulness. Contextual factors do not act as uniform predictors but are filtered through usability and value-based paths before adoption occurs. Technological and organizational factors operate through differentiated perceptual pathways: perceived financial benefits and information security strongly enhance usefulness, whereas complexity mainly reduces ease of use. Among environmental factors, partner readiness exerts a stronger effect on adoption than competitive pressure. The results also support a sequential perceived ease-of-use–perceived-usefulness–adoption mechanism across TOE dimensions. Originality/value – The study moves beyond additive TOE–TAM integration by establishing a theoretical chain that explains blockchain adoption as a multistage process. It contributes by providing evidence of a sequential ease-of-use–usefulness–adoption mechanism and by showing that, in financial institutions, TAM operates hierarchically rather than symmetrically, with usefulness emerging as the primary adoption mechanism.