Sweet basil (Ocimum basilicum L.) seeds exhibit heterogeneity due to the characteristic flowering and pollination process of this species. Consequently, the necessity for research geared toward establishing effective methodologies for identifying seeds capable of germinating and with potential for producing vigorous seedlings becomes apparent. This study was undertaken with the aim of assessing the relationship between internal morphology, as evaluated through radiographic image analysis, and the germination performance of sweet basil seeds. Radiographs of seeds from eight lots of the cultivar Alfavaca Basilicão were examined. The length of seedling originated from radiographed seeds was obtained through computerized image analysis using SVIS® software and the results were compared with the radiographic images. Radiographs allowed visualization of the internal morphology of sweet basil seeds, enabling the identification of empty seeds, malformed seeds, seeds with tissue deterioration and mechanical damage. The analysis of radiographic images substantially contributed to establishing a cause-and-effect relationship between the physical integrity of tissues and the germination performance of the seeds, underscoring the potential for selecting seeds that will contribute to enhanced lot quality.