Spain will create a list of people who refuse to be vaccinated against Covid-19 when they are offered jabs under the vaccination campaign.
Health Minister Salvador Illa said vaccination was voluntary and there would be no consequences for those who refuse to take the shots.
Although he added that the information would be shared with Spain's EU colleagues.
"We will have a registry... of those people who have been offered [the vaccine] and have simply rejected it," Mr Illa told Spain's La Sexta TV channel.
"It is not a document that will be made public and it will be done with the utmost respect for data protection."
Mr Illa said registering people's rejection of the jabs would avoid confusion over why certain individuals had not been vaccinated when it was their turn.
Spain started administering the Pfizer vaccine on Sunday.
A poll from early December on people's willingness to be vaccinated carried out by the state CIS research body showed 28pc of Spaniards said they would refuse the shots, down from more than 40pc in September.
Spain's health ministry plans to deploy an average of 350,000 shots of the Pfizer vaccine per week over the next three months.
The country's official number of deaths from Covid-19 has now topped 50,000.