They are Chumphon, Krabi, Nakhon Si Thammarat, Phatthalung, Phuket, Songkhla, Surat Thani and Trang, according to the Election Commission.
Thirty-eight candidates could not register their names in the venues, except for Phuket where one Pheu Thai Party member was successful, EC secretary-general Puchong Nutrawong said.
Protesters locked the registration venues so that election officials and candidates could not go inside or surrounded the places to seal them off from politicians, reporters covering events said.
The EC found no problems in other provinces in the country.
Constituency MP candidates have until Wednesday to apply for the election run.
Mr Puchong warned the protesters of legal action after the deadline if they still tried to derail the registration period.