Resumo:Introdução: Atuais pesquisas sobre intervenção precoce (IP) em bebês com risco ao desenvolvimento -entre os quais, o prematuro -convidam terapeutas à construção de novos tratamentos clínicos. Objetivo: Analisar a eficácia de uma Hipótese de Funcionamento Psicomotor (HFP) para tratamento de bebê prematuro. Método: Tem cunho qualitativo, longitudinal, clínico quase experimental, de estudo de caso único. Amostra deu-se por conveniência, sendo um bebê prematuro, com risco psíquico e de desenvolvimento, identificado pelos protocolos PREAUT e IRDIS. longitudinal, and clinical almost experimental single case study. We studied one premature baby, with developmental and psychic risk, identified by the PREAUT and IRDI protocols. The baby received three months of PI treatment by occupational therapy from the HPF. Treatment was filmed and registered in a field diary. We then compared the proposed objectives and the collected results, outlining the effects of the HPF. Results: The case confirms that the psychomotor irregularity may be understood as a psychomotor symptom and its source construed as from a HPF.The irregularity is considered in a singular way, as observation of how the child constructs its Body Scheme (BS) and Body Image (BI), starting from the bonds with parents. The treatment effectiveness was confirmed from a HPF, as the psychomotor symptom went away (BS), giving place for cognitive and psychomotor acquisitions, and to