The radiation crosslinking of poly(l-lactide) (PLLA) was investigated using triallyl isocyanurate (TAIC) as a crosslinking agent. The gel fraction of crosslinked PLLA increased with TAIC concentration and gamma-ray dose. Crosslinking of PLLA started at low TAIC contents and low gamma-ray dosage. Differential scanning calorimetry and dynamic mechanical thermal analysis revealed that PLLA was completely crosslinked at high weight ratios and high gamma-ray doses.