Odair married Annemarie Martha Eggert daughter of Max Johann Eggert and Anne Catharine Eilerts.
They had the following children:
2 F i Ellen Heidi Costa + 3 F ii Erika Heike Costa 4 F iii Evany Hanne Costa 5 F iv Evelyn Helga Costa Evelyn married Roberto Valdrez Junior. + 6 M v Edgar Eggert Costa