Is the word importar the same in Brazilian and European Portuguese?

No.

While the fundamental meaning of "importar" (to import or to matter) is identical in both dialects, there is a significant difference in grammar (specifically clitic placement) and pronunciation. In Brazil, the reflexive pronoun is typically placed before the verb (proclisis), such as "Você se importa?". In Portugal, the pronoun is traditionally placed after the verb (enclisis), such as "Importa-se?". Additionally, the pronunciation of unstressed vowels is much more "closed" in Continental Portuguese, whereas Brazilian Portuguese tends to have more "open" vowels.

Brazilian Portuguese Examples

1. Você se importa de me ajudar com isso? (Do you mind helping me with this?)
2. Não me importa o que eles vão dizer. (I don't care what they are going to say.)
3. Eu não me importo de esperar um pouco mais. (I don't mind waiting a little longer.)
4. O que importa é que a gente chegou bem. (What matters is that we arrived safely.)
5. Isso não vai me importar muito. (That won't matter much to me.)

Continental Portuguese Examples

1. Importa-se de me ajudar com isto? (Do you mind helping me with this?)
2. Não me importa o que eles dirão. (I don't care what they will say.)
3. Não me importo de esperar um pouco mais. (I don't mind waiting a little longer.)
4. O que importa é que tenhas chegado bem. (What matters is that you have arrived safely.)
5. Isso não me irá importar muito. (That will not matter much to me.)