Mohammed Haji Sadiq, 81, is accused of sexually touching girls aged between five and eleven at his Quran classes.
Cardiff Crown Court heard Sadiq allegedly felt the stomach, chest and private parts of the young girls – and would also pull them towards him to rub their body against the inside of his legs.
It is alleged that Sadiq would abuse the girls after calling them to sit next to him so he could listen to them recite the Quran.
The court heard he taught primary school children who called him ‘uncle’ at the Madina Mosque in Cathays in Cardiff for 36 years.
Prosecutor Suzanne Thomas said: “He took advantage of his position to touch in a sexual manner four young girls who were in his care.
One of the victims, now 26, said how she was abused several times per week.
“She describes being asked to sit next to the defendant with the Quran and he asked her to sit on his lap,” said Miss Thomas.
“Sometimes he laid her face down on his lap and touched her between her legs.”
The woman – who cannot be named – appeared in court via a video link and her police interview from May of last year was played to the jury.
She attended Quran lessons with Sadiq for four years starting when she was six years old.
The Madina Mosque was shut down in November 2006 after fire damage.
Sadiq has attended a different mosque since the fire and never returned to the Madina Mosque.
Sadiq, of Cyncoed, Cardiff, denies seven counts of indecent assault of a girl under 14, and eight counts of assaulting a girl under 13 by touching.
The trial at Cardiff Crown Court continues.