The 23-year-old, who has not been identified, feared that if forcibly returned to his homeland he would face persecution for having renounced his faith.
The Home Office's decision to accept denial of the existence of God as grounds for protection could set a significant precedent in asylum and immigration cases. The application was granted before the hearing stage at an immigration tribunal.
The Afghan was brought up as a Muslim and fled the conflict in his native country. He arrived in the UK in 2007, aged 16. He was initially given temporary leave to remain until 2013 but during his time in England gradually turned to atheism.
His case was taken up by Kent Law Clinic, a free service provided by students and supervised by qualified practising lawyers from the University of Kent's law school along with local solicitors and barristers.
They helped him submit his claim to the Home Office under the UN's 1951 refugee convention, arguing that if he returned to Afghanistan he would face persecution on the grounds of religion – or in his case, lack of religious belief.