Campaigners from WASPI (Women against state pension inequality) braved Storm Dennis to protest outside Cardiff Castle.
They say they've been left out of pocket since the UK Government increased the state pension age for women to 65.
The women affected were born in the 1950s. They claim they were given little or no notice of the government's plans, meaning they were unable to make proper provision for their retirement.
Protestors say many are now unable to find work and are resorting to zero hours contracts, the support of family and partners, and even food banks.
So many women are in such dire straits now. Women are having to sell their homes, some of them are taking heir own lives because they simply cannot survive with no income whatsoever. Our pensions were stolen from us and we were given little or no notice.
Plans to equalise the state pension age for men and women were first proposed by the UK government in 1995, with changes starting to come in in 2010.
By 2018, both men and women were receiving their state pension at 65. In October this year, the threshold is scheduled to rise to 66, with a further increase - to 67 - set to come in between between 2026 and 2028.
In a statement, the Department for Work and Pensions said the move had been "clearly communicated" and was a "long-overdue move towards pensions equality."
"The government decided more than 20 years ago that it was going to make the State Pension age the same for men and women as a long-overdue move towards gender equality, and this has been clearly communicated.
But feelings were running high when protestors gathered in the capital city today, despite the appalling conditions.
Sue Donovan from the WASPI group summed up the mood, saying the government had "gone back" on a contract they'd made with women.
"We entered into a contract when we started work, and we trusted them that they would pay out. They've actually gone back on that. If they'd had that done to them it would be a different matter altogether."
Campaigners now want the new chancellor Rishi Sunak to look again at the issue ahead of the budget, scheduled to be in less than a month's time.