We report on the XMM-Newton observations of two milli-second pulsars PSR J0538+2817 and PSR B1706-44. We present evidence for the first detections of pulsed X-rays from PSR J0538+2817 at a frequency which is consistent with the predicted 143 ms radio period. The spectrum of PSR J0538+2817 can be well-fit with a single blackbody with T = (2.12 +/- 0.04) x 10^6 K. The resulting blackbody radius is 1.68 +/- 0.05 km, indicating that the emission is not from the whole surface of the neutron star, but rather from a heated polar cap. The 90 ks observation of the 102 ms pulsar PSR B1706-44 displays pulsed X-ray emission which is again consistent with the predicted radio period. The spectrum can be well-fit with a two component model with T = (1.84 +/- 0.08) x 10^6 K and power-law index 1.7 +/- 0.1. The blackbody radius is 2.82 +/- 0.26 km. The spectra of both sources can also be well-fit with an atmospheric model, which reduces the inferred temperature and hence increases the radius of the emitting region.