The kits produced by US firm White & Blue Lion, Inc could be contaminated at a microbiological level, the Spanish government's medical regulator Aemps have said in a statement.
The warning comes after the US's Food and Drugs Administration (FDA) said the company had voluntarily taken the drugs off the market.
The agency warned use of the products could lead to infection and life-threatening sepsis.
The White & Blue Lion, Inc products in question are not licensed for use in Spain. But Aemps says the products could have been imported into Spain illegally and may be available on the black market. People may have also purchased them online.
Customers who have used the tattoo kits and who are experiencing symptoms including high fever should see a doctor, the watchdog said.
Full details of the dodgy products can be found on the FDA website.