As is the case in most European destinations, adding gratuity to a bill is optional and therefore not necessarily expected. This concept can be difficult to swallow for those of us who come from cultures where service workers rely on tips. The salary structure for employees in the service industries in Amsterdam (e.g., food servers, taxi drivers, hotel bellhops) is much different than, for example, that of their American counterparts. They are paid fully by their employing establishments and do not need tips to supplement their incomes.

That said, it is not uncommon to round up a bill to the nearest whole euro or leave extra small coins (slightly more for larger bills) if You feel you've received very good service. Tips will certainly be appreciated and, in my opinion, there is nothing wrong with bringing a little bit of your own culture (i.e., one where tipping is the norm) to a foreign place. My Amsterdammer friends might disagree with me -- when I go out with them, they rarely tip. In short, the decision to leave gratuity is entirely up to the patron.

Source : GoAmsterdam.com