The council asked people who were due a Friday collection to leave their bin out, so the rubbish could be collected as soon as possible.
A group called Strike Map, which records the locations of strikes around the country, said it had co-ordinated the day of action.
It said it expected thousands of trade unionists to visit the city for the pickets.
The co-founder of Strike Map, Henry Fowler, said there would be more co-ordinated pickets until the strike was resolved.
Unite is in dispute with Birmingham City Council over several changes the local authority is making, including getting rid of a job role within the refuse operation and cutting another role’s pay.
The council said it was “forging ahead” with transformation of the waste service, which needed improvement.
Unite claims that the council is now refusing to negotiate, but the local authority maintains the union has rejected “fair and reasonable” offers.
Earlier in the week, the city council reported that protesters were blocking the entrances to its depots, causing delays to departing bin lorries.
In some areas of the city, bins have not been emptied for a second week in a row, causing rubbish to build up on pavements.