Tobacco seeds (Nicotiana tabacum L. cv KF109) were primed in the polyethylene glycol 6000(PEG) solution and then stored at 5 and $25^{circ}C$ under 40, 60 and 80% relative humidity (RH) conditions for six months. The effect of storage temperature and humidity on mean germination time ($T_{50}$), longevity and germination of the primed tobacco seeds were compared. Untreated seeds (control) stored at $5^{circ}C$ showed high germinability throughout the entire storage period and humidity, and a decline in germinability showed after 6 months at 60% RH and after 3 months at 80% RH when stored at $25^{circ}C$, Primed seeds retained high germinability until 6 months at 60% RH and 3 months at 80% RH when stored at $5^{circ}C$ but showed a significant decline in germinability after 3 months at 40% RH, and 1 months at 60% and 80% RH, respectively when stored at $25^{circ}C$, Primed seeds were completely lost viability when stored at $25^{circ}C$ under 60% RH for 6 months and under 80% RH for 3 months.