Flax has the potential to become an important oilseed crop for bio-products and is well adapted to the cropping systems of northcentral Montana. Little information on the response of flax to N and P fertilization is available; consequently, nutrient management research was initiated in 2004 at four locations. Nine treatments consisting of 0, 30, and 60 lbs N/acre in combination with 0, 15, and 30 lbs P2O5/acre were applied at planting in a factorial, RCB design. Average yields ranged from 425 to 1243 lbs seed/acre; two locations responded to N while only one responded to P fertilization. Seed oil contents averaged between 41% and 42% and declined slightly at all locations as N levels increased. Phosphorus fertilization increased seed oil content slightly at the location that experienced the P yield response. Palmitic fatty acid levels averaged 3.3 to 3.8 % of the oil content, oleic averaged 15.5 to 17%, linoleic 14.8 to 17.7%, and linolenic 53.8 to 61.6%. Oleic and linoleic fatty acid levels were unaffected by N and P fertilization; however, palmitic levels declined with increasing N at one location and increasing P at another location. The most important fatty acid, linolenic, declined slightly with increasing N at one location but was unaffected by P. All N and P interactions were non-significant.