Cardinal Gianfranco Ravasi, president of the Pontifical Council for Culture, was speaking at an event for believers and non-believers in Mexico City, BBC reported.
The cult, which reveres death, has been growing rapidly in Mexico.
It is represented by a cloaked female skeleton clutching a scythe.
It is particularly popular in areas of Mexico that have suffered from extreme violence carried out by the country's drug cartels.
The cult is believed to date back to colonial times.
Cardinal Ravasi said the practice was "anti-religious".
"Religion celebrates life, but here you have death. It's not religion just because it's dressed up like religion; it's a blasphemy against religion", he said.
The cardinal said the cult is particularly popular among Mexico's drug cartels and accused "criminals" of invoking it.
BBC said there is no reliable data showing how many people worship Santa Muerte.
Last year, police in Mexico arrested eight people in connection with the killing of two boys and a woman in ritual sacrifices which prosecutors said were linked to the cult.
--IANS (Posted on 10-05-2013)