Egyptian Prime Minister Ahmed Nazif. "received Mr Hosni and they discussed the minister's resignation and agreed to consider it null and void," said Salah Issa, editor in chief of Al-Qahira weekly, published by the ministry.
Hosni, who had been in the job for 18 years, tendered his resignation on Wednesday in the face of intense criticism over the tragedy.
A state-run theatre caught fire in the town of Beni Suef on the banks of the Nile south of the capital on 5 September, killing 46 people and injuring dozens more.
The blaze was apparently caused by candles used during a production that set fire to paper decorations, blocking the main entrance and triggering a stampede as spectators scrambled to the theatre's only other exit.
Eight people have been detained over the blaze and face charges of negligence.
Resignations by government members are very rare in Egypt, but Hosni's many years at the helm of the Culture Ministry have been tarnished by accusations over antiquities smuggling and controversial policies.