Authorities found a nitrogen tank containing the vials in the man’s bag when he was crossing the border at the northern Thai town of Nong Khai.
Police said the man confessed that the semen was bound for a fertility clinic in the capital of Laos – Vientiane.
Laos has seen a boom in commercial surrogacy after neighbouring Thailand and Cambodia banned the practice.
The semen was collected from Chinese and Vietnamese men, police said.
The smuggler, a Thai national, told police he had done 12 similar trips in the past year where he would collect semen from Bangkok clinics and transport them to the clinic in Laos, reported The Bangkok Post newspaper.
He said he had also done several deliveries to a hospital in Cambodia, the paper reported.
In 2015, Thailand banned foreigners from paying Thai women to act as surrogates following a string of scandals in the once thriving industry. Cambodia followed with a total ban last year.
This has coincided with a rise in the number of Laos-linked surrogacy agencies and fertility clinics, reported AFP news agency.