More than 500 activists gathered outside parliament in the capital Kuwait City for the third week in a row after authorities jailed opposition leader and former lawmaker Mussallam al-Barrak for allegedly insulting the emir.
The previous two gatherings were peaceful and passed off without police interference.
But as a few dozen protesters marched towards parliament on Monday, police used batons to beat activists, forcing them to disperse.
Kuwait National Committee for Monitoring Violations, a private rights group, said on Twitter that several protesters were hurt and others were arrested.
Earlier in the day, the interior ministry had warned protesters to abide by a law that regulates rallies.
The Kuwaiti opposition has stepped up its demands for the dissolution of the parliament and government and the scrapping of a controversial electoral law.
Since tens of thousands took to the streets in 2012, Kuwaiti authorities have cracked down on the opposition. Dozens have been tried and handed heavy jail terms.
The crackdown, which has also seen several opposition figures stripped of their citizenship, has been condemned by rights groups, who have called for reforms to stop people being jailed for exercising free speech.