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

No

While the fundamental definition of the word (business, commerce, or a deal) is identical in both dialects, there is a difference in typical usage. In Brazilian Portuguese, "negócio" is frequently used colloquially as a placeholder for an unidentified object, person, or situation (similar to how an English speaker might use "thing" or "stuff"). In Continental Portuguese, while "negócio" is used for trade, a speaker is much more likely to use the word "coisa" to refer to an unnamed object or an abstract matter. Additionally, the pronunciation differs: Brazilian Portuguese features more open vowels, whereas Continental Portuguese features more closed, reduced vowels.

Brazilian Portuguese Examples

1. "Preciso resolver um negócio rápido." (I need to resolve a matter quickly.)
2. "O que é esse negócio que está na sua mão?" (What is that thing in your hand?)
3. "Abrimos um negócio de café no centro." (We opened a coffee business downtown.)
4. "Aquele negócio que você me vendeu quebrou." (That thing you sold me broke.)
5. "O negócio entre eles não é da minha conta." (The business/affair between them is none of my business.)

Continental Portuguese Examples

1. "Tenho uma coisa para resolver rapidamente." (I have a matter to resolve quickly.)
2. "O que é essa coisa que tens na mão?" (What is that thing in your hand?)
3. "Abrimos um negócio de café no centro." (We opened a coffee business downtown.)
4. "Aquela coisa que me vendeste partiu-se." (That thing you sold me broke.)
5. "O negócio entre eles não é da minha conta." (The business/affair between them is none of my business.)