Around an hour after the evacuation, first staff and then those customers who stayed on site were allowed back in the shop.
IKEA said the mass evacuation was to allow it to investigate a safety concern.
A spokesman for the Swedish flat-pack furniture chain said: The safety of our customers and co-workers is always the highest priority for IKEA.
We can confirm that all customers and co-workers exited our Birmingham store at 14:15 today to allow us to investigate a safety concern.
The store reopened at 15:15. We apologise for the inconvenience caused."
West Midlands Police then confirmed the evacuation was due to a suspicious item being found at the site shortly before 2pm but the nature of the item was not revealed.
A spokesman for the force said: We were called to Ikea in Wednesbury at around 1.52pm following a report of a suspicious item.
The store was evacuated while the building was searched and has since re-opened.
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