The court found 47-year-old Suthep Chabangbon guilty on Thursday of hiding 15 fetuses in the temple's mortuary last year.
He was one of two undertakers hired by illegal abortion clinics to destroy fetuses.
A second morgue worker who had hidden nearly 2,000 fetuses in the mortuary was sentenced to 20 years in jail earlier this year. Both men were charged with damaging and concealing criminal evidence.
A clinic employee also received a five-year jail term for performing illegal abortions.