In Saskatchewan and other Prairie Provinces, most canola is grown in the Parkland zone where many soils are deficient or potentially deficient in S for high seed yields of canola. On soils marginally deficient in S, combination of high rates of N fertilizers, high yielding canola cultivars and continuous cropping result in faster depletion of S in soil and increase instances of S deficiencies in canola in the growing season. This can cause substantial reductions in seed yields, apparently due to N:S imbalance in canola plants. Information on the effects of different combinations of fertilizer N and S rates (N:S ratios) on frequency and severity of S deficiencies, and on yield and quality of canola seed is lacking. The objective of this study was to determine the influence of fertilizer N:S ratios (combinations of different N and S rates) on seed yield and quality of canola.