"Ile masz dolarów?"

Translation: How many dollars do you have?

[cicilanov]

That's because "ile" requires Genitive. It's actually like "Ile dolarów masz?"

[Zkamin]

I apologize for asking this, but does the verb mieć take dopełniacz afterwards when it has "ile"??? I know for general case, mieć should take biernik: such as Mam kota(koty).

[Jellei]

Yes, you're perfectly right.