Flax ( Linum usitatissimum L.) is an annual, diploid plant that belongs to Linaceae family. It is the only economically valuable species in this family and can be grown as a single or dual-purpose crop for its oil (linseed) and its fiber (flax). In general, flax can be used for industrial purposes, human nutrition or animal feed. Petal color is most commonly blue or white, but pink and purple flowers have also been reported. The most frequent seed colors in flax are brown and yellow, which is controlled by one to four genes (G, D, B1 and Y1). Reports on the inheritance of these traits have indicated that the white flowers are associated with yellow-seeded and the blue flowers with the brown-seeded types. Considering the importance of the seed color and the availability of flax genotypes with reciprical combination of seed and flower colorsthis research was set to determine the number of genes involved in controlling the seed and flowercolor, identify the genetic relations between the two traits and the presence of linkage between the genes. Four flax genotypes including Indian (brown seed, white flower), 76 (brown seed, blue flower), 47 (yellow seed, white flower) and Golden (yellow seed, blue flower), were crossed in all combinations. The correlation of expected ratios with the observed ratios based on the chi-square test was performed for F 2 generation data at 95% confidence level. The results showed that the seed coat color of the F 1 genotype was under maternal influence. The presence of a dominant gene for yellow seed color in the Golden genotype and the presence of a dominant gene for brown-seedwere observed in the two genotypes with brown seed color. Dominance of blue to white flower was evident among the genotypes. For the three genotypes of Indian, Golden and 76 no likage was observed between the seed and flower colors and no association was found between the two traits. On the other hand, the results obtained from the inter-crossingsof genotype 47 and other parents suggested that the color of the flower in this parent is controlled by more than one gene and may have interaction with other genes. Also the possibility of linkage between seed and flower color in this genotype could not be overruled. Key Words Linseed, Seed color, Flower color, Inheritance