This study is aimed to increase the knowledge about the Swedish immigration authorities’ assessment of the asylum applications based on particularly distressing circumstances, submitted by disabled undocumented migrants. Making an attempt to explain the reasons of asylum-seekers’ health deterioration during the asylum process, this study determines the factors in migration authorities proceedings affecting such deterioration. Documents in five personal files concerning six disabled asylum-seekers, whose applications were declined, were studied by applying two observational methods: content analysis of the documents in the personal files and non-participant observations made during receptions of undocumented migrants at the Swedish Asylum Committee. The results of the study have shown that migration authorities' way of applying the principle of child’s best interests have a declarative character, while the disability perspective is completely ignored. The migrations authorities make free interpretations of the information on the countries of asylum-seekers' origin, while adaptation to Swedish conditions does not work at all as cause for residence permit. Advocates, who neglect their prior duties, have also a negative influence on the asylum process. Analyzed from the perspective of appropriate sociological concepts, the results of this study have shown that the above mentioned observations cause disabled undocumented migrants health deterioration.