Labour sees room for improvement, after a report praising the professionalism of New Zealand teachers.

The OECD study ranked teachers here as the fourth most professional out of 34 developed countries.

Labour's education spokesman Chris Hipkins said it's good to know teachers are performing well, but he's worried where the next generation will come from.

"The simple reality is you can't afford not to, we've got an aging teaching profession - a number of them are going to be nearing retirement in the next decade. We're going to be recruiting and training people to replace them."

Mr Hipkins said industries are changing more rapidly than ever before and training needs to keep up with that.

"I think the risk is if we don't invest in teacher professional development and ongoing support for teachers then we will start to slip behind."

Yesterday NZEI president Louise Green said the OECD study of 34 countries shows we're fourth best... but if we kept up the funding across the curriculum, we'd be in first place.

She said this study confirms what she's known all along - our teachers are well-trained and qualified nation-wide, and are doing a great job for our kids.