Analyses were made for non-saponifiable matter, iodine value, thiocyanogen value, and saturated acids on 54 samples of linseed oil from three varieties of flax grown in Saskatchewan. From these data the percentages of oleic, linoleic, and linolenic acids in the oils were computed. Analysis of variance showed that varietal differences exist for all these properties with the exception of non-saponifiable matter, and environmental effects cause significant differences in all properties.Highly significant total correlation coefficients were obtained between iodine value and:—thiocyanogen value, r =.962**; saturated acids, r = −.596**; unsaturated acids, r =.692**; oleic acid, r = −.912**; and linolenic acid, r =.940**. Relations between iodine value and thiocyanogen value, linolenic acid, linoleic acid, and oleic acid proved to be homogeneous with respect to regression coefficients and centroids. From these relations the following prediction equations wrere derived:Thiocyanogen value = 0.44 iodine value + 38.59 (S.e. = 0.63 units);Linolenic acid, % = 0.49 iodine value − 37.93 (S.e. = 0.88%);Linoleic acid, % = 0.055 iodine value + 0.73 (S.e. = 1.80%);Oleic acid, % = −0.48 iodine value + 113.08 (S.e. = 1.06%).** Indicates that the 1% level of significance was attained.