Two men, both 27, from Qormi, pleaded guilty to stealing diesel from a trailer in Marsa.
Stephen Cassar and Alan Azzopardi admitted to the theft which took place on Saturday.
Magistrate Doreen Clarke noted that Mr Azzopardi committed the crime during the period of a suspended sentence and a probation order.
She gave him a 16-month jail sentence, adding a further eight months of his previous suspended sentence, bringing it to 24.
Mr Cassar was placed under a two-year probation order.