Hundreds of Swazi women have marched through the streets to protest about a shopping trip taken by nine of the king's 13 wives.
They chartered a plane last week to go to Europe and the Middle East.
The BBC reports the protesters delivered a petition to the Swaziland finance ministry saying the money could have been better spent.
"We can't afford a shopping trip when a quarter of the nation lives on food aid," they chanted.
"We need to keep that money for ARVs [anti-retrovirals]" was another slogan.
Swaziland, Africa's last absolute monarchy, is one of the poorest countries in the world and more than 40% of the population is believed to be infected with HIV.
The march was organised by Positive Living, a non-governmental organisation for women with Aids.
King Mswati III, 40, has been criticised in the past for requesting public money to pay for new palaces, a personal jet and luxury cars.