Managers at Cineworld on the Valley Centertainment complex opposite The Arena announced earlier today that the cinema had been closed for 'health and safety' reasons.
No explanation was provided, but it is understood a fault with the lighting was to blame.
The cinema has just announced that the complex has re-opened.
It was closed for around 45 minutes.
A spokesman said: "We are open, a little technical gremlin doesn't stop us for long.
"Thank you for understanding."