Purpose :To assess functional and morphological aspects of spleen auto-implants and of the splenic inferior pole of rats, post-operatively treated or not with hyperbaric oxygen, as well as the survival of these animals, were studied. Methods: Seventy-eight male Wistar rats, weighing between 192 and 283 g ( 238,3 ± 9,6g), were randomly distributed into three groups: Group1-(n=20), spleen manipulation; group 2-(n=36), spleen auto-implantation; group3-(n= 22), subtotal splenectomy preserving the inferior pole. Each group was subdivided as follows: subgroup a, not submitted to hyperbaric oxygen therapy: 1a(n=10), 2a(n=21), 3a(n= 13); subgroup b, submitted to the therapy: 1b(n=10), 2b(n=15), 3b(n=9). Blood was collected pre-operatively and 11 days after surgery, for the estimation of lipids and immunoglobulins and the counting of platelets and Howell-Jolly corpuscles. The spleen and remains were taken for histological study. Results : The number of surviving animals was significantly higher in groups 1(p<0,01) and 3(p<0,05) relative to those of subgroup 2a. Total cholesterol and the LDL fraction increased significantly in subgroup 2a (p<0,01) and 3a (p<0,05), and remained unaltered in subgroups 2b e 3b. IgM decreased more significantly in subgroup 2 than in subgroup 3 (p<0,001 vs p<0,01). The increase of platelet numbers and the appearance of Howell Jolly corpuscles was smaller in subgroup 2b compared to subgroup 2a , and in group 3 compared to group aqui-> 2. The macro and microscopic appearance in subgroup 2b were more viable than in subgroup 2a, and that of group 3 more viable than in group 2. The survival of the animals carrying their whole spleen or its inferior pole was more frequent than that of the auto-implanted animals. Conclusion : Functionality and viability of the whole spleen or of its inferior pole, were better than in the auto-implanted animals. Hyperbaric oxygentherapy contributed to increased survival frequency of auto -implanted animals, and to improve the functionality and viability of the auto-implants and the function of the inferior splenic pole, and did not interfere in animals carrying their whole spleen. Key words: Splenectomy/methods.Spleen/metabolism. Adverse effects/splenectomy. Oxygen inhalation therapy/methods RESUMO Objetivo : Estudar aspectos funcionais e morfológicos dos auto-implantes esplênicos e do pólo inferior do baço de ratos, tratados ou não com oxigênio hiperbárico no pós-operatório, e a sobrevida desses animais. Métodos: Foram operados 78 ratos, machos, Wistar, pesando entre 192 g e 283 g ( M.A 238,3 ± 9,6) , distribuídos aleatoriamente em três grupos : 1-(n=20) , manipulação do baço; 2-(n=36), auto-implante esplênico; 3(n= 22), esplenectomia subtotal com preservação do pólo inferior. Cada grupo foi dividido em dois subgrupos: a-não submetido à oxigenoterapia hiperbárica: 1a(n=10), 2a(n=21), 3a(n= 13); b-submetido: 1b(n=10), 2b(n=15), 3b(n=9). O sangue foi colhido para dosagem dos lípides e imunoglobulinas e contagem das plaquetas e dos corpúsculos de Howell-Jolly n...