A diallel crossing design was carried out during 1999 and 2000 seasons near Montpellier under field nursery conditions. Intercrosses of seven sunflower lines were performed between genetic (ms2) or cytoplasmic male sterile (PET1) and standard versions using bagged heads. These lines contrasted for oleic acid content in oil. Four lines with high oleic acid content originated from Pervenets. Three linoleic inbred lines were added to the crossing design. Male fertile lines were selfed in the same conditions. F1 seeds and those from selfed inbred lines were analyzed for fatty acid composition using gas chromatography. Year effect, reciprocal or maternal effects, general combining ability and specific combining ability effects were found to be significant. The level of dom inance of high oleic acid content appeared related to the genetic background. We found previously that 83HR4, a linoleic line of the diallel, was bearing a suppressor allele canceling Pervenets mutation effect. In reciprocal crosses with high oleic lines, this line had a strong maternal negative effect on oleic acid content.