Provided are a polybutylene terephthalate resin composition which is excellent in mold releasability and which can suppress deterioration in molding stability and aggregation of the polybutylene terephthalate resin composition due to blooming of a mold release agent; and a pellet thereof. The polybutylene terephthalate resin composition contains 0.01 to 5.0 parts by mass of (B) a saturated fatty acid ester of a polyglycerol represented by formula (I) described below with respect to 100 parts by mass of (A) a polybutylene terephthalate resin. In formula (I), R1s each may be the same or different and are C19-30 saturated aliphatic acyl groups, and n is an integer from 1 to 10.