In fact with one in five Spaniards insisting that they are "convinced atheists" Spain ranks fifth on the global list of adamant non-believers.
The study by polling firm WIN/Gallup surveyed 63,398 people in 65 countries in a bid to discover global religious trends.
Spain was surprising in that only 37 percent described themselves as "religious" while 35 percent said they were “not religious” and 20 percent went even further and declared that they were "convinced atheists".
Once the bastion of Roman Catholicism, Spain was responsible for the Inquisition and the birth of orders including the Dominicans, the Jesuits and Opus Dei, the religion has been on the wane since the death of dictator General Francisco Franco in 1975.
The last Pope, Benedict XVI, saw Spain as one of the principle nations ripe for evangelism and visited the country three times in his eight year as pontiff.
But the number of churchgoers has continued to fall.
According to the survey, only China (61 percent), Hong Kong (34 percent), Japan (31 percent) and the Czech Republic (30 percent) registered more "convinced atheists" that Spain.
In Western Europe, approximately half of the population described themselves as "not religious" or "a convinced atheist" in the survey.
Thailand was the most religious country globally in the latest WIN/Gallup poll, with more than nine out of ten respondents descibing themselves as religious. Bangladesh, Georgia and Morocco were ranked joint second.
Jean-Marc Leger, President of the WIN/Gallup International Association, said that religion continued to dominate the lives of most global citizens.
"We see that the total number of people who consider themselves to be religious is actually relatively high. Furthermore, with the trend of an increasingly religious youth globally, we can assume that the number of people who consider themselves religious will only continue to increase."
The popularity of religious processions that occur across Spain during Easter week may appear to tell a different story but the statistics do show that even those who consider themselves religious only go to church infreqiently.
A recent poll by the Spanish think tank CIS claimed that 69 percent of respondents considered themselves Catholic, 16 percent non-believers and 10.3 percent atheists.
But 60 percent admitted to almost never attending church while only 11.9 percent claimed that they went every Sunday and on Saints’ days.