Updated 12.35pm: The number of New Zealand women in the top job has reached an all time low.

Only 19% of senior management positions in the businesses surveyed by Grant Thornton International are held by women.

New Zealand is ranked 28 out of the 35 countries surveyed.

Grant Thornton New Zealand's Stacey Davies says it's a worrying downward trend.

But she says women need to take matters into their own hands.

Ms Davies says they can't just sit back and wait to be invited to the top table - they need to invite themselves or push to be invited.

"People sometimes just assume that people potentially don't want the role, or they're quite happy doing what they're doing."

"Unless you actually make it known that you do want to progress, you kind of have to make the step yourself and let people know."