We derive an upper limit on the neutrino mass from the WMAP three-year data alone by employing a deterministic minimisation method based on a grid search in multi-parameter space .
Assuming the flat \Lambda CDM model with power-law adiabatic perturbations , we find \sum m _ { \nu } < 2.0 eV in agreement with the result of the WMAP team .
This result , the limit being nearly the same as that from the WMAP first-year data , means that the fundamental limit on the neutrino mass obtainable from the cosmic microwave background alone is already nearly met , as anticipated from the previous analysis .
We also clarify the role of the polarisation data in deriving the limit on the neutrino mass .