Crews from Hereford and Worcester fire and rescue service were called to the barn fire at Clows Top, near Bewdley, at 2.56am.
Three fire engines and a water carrier were dispatched, including one engine sent from Shropshire fire and rescue service, to try and tackle the blaze.
Two water jets were also used.
No one was hurt in the fire and crews decided to initiate a 'controlled handling' of the blaze to allow it to burn itself out.
The owner of the barn was instructed to monitor the situation and let emergency services know if further assistance was needed.
Fire crews left the scene at 7.19am before reinspecting the site at around midday.