Fire officers tackled a blaze involving 15 cars at a scrap metal merchants - the second at the same property in the space of two months.
Crews from Morriston responded to an emergency call shortly after 11am, and went to fight the fire, which also involved tyres, at Abertawe Metals in Dyffryn Close, Swansea Enterprise Park, Llansamlet .
The scrap metal merchants was also visited by firefighters in February , who spent three hours at the site after an emergency call at around 3am.
Mid and West Wales Fire and Rescue Service said two hose reel jets, a main jet and breathing apparatus were used to bring the latest fire under control.
"Fire was involving 15 motor vehicles & commercial vehicle tyres," said the fire service in a tweet.
The incident, which the service said was accidental, was over by midday.
A South Wales Police spokesman said: "At around 11.45am today police were called to assist the fire service following a report of a fire at a scrap metal yard in Llansamlet.
"The cause of the fire is not suspicious.
"Officers attended to ensure sufficient access for the fire tenders."
