In an integrated pest management perspective, combining several levers can enhance pest control efficacy. Previous studies have shown that oilseed rape (OSR, Brassica napus) grown with companion plants disrupts crop colonisation by insect pests, partly through visual and physical mechanisms. In addition, varietal resistance in OSR has been demonstrated to significantly reduce Psylliodes chrysocephala larval infestation, likely due to differences in glucosinolate profiles. Sulphur application, particularly through foliar spraying, may provide an additional chemical disruption that complements companion planting. Furthermore, both the quantity and timing of dry sulphur application could influence glucosinolate production and thereby affect OSR antixenosis. An open-field experiment was designed to assess the combined effects of the three levers: (I) sulphur fertilisation, (II) varietal resistance, and (III) cropping system (with or without companion plants). The study evaluated flea beetle feeding damage (from Phyllotreta spp. and P. chrysocephala) during early OSR development, as well as P. chrysocephala larval infestation. Additionally, the effects of treatments on glucosinolate profiles and plant nutritional status were analysed. Preliminary results showed no interaction among the three factors regarding flea beetle feeding damage. Both companion planting and varietal resistance significantly reduced the number of feeding shot-holes, whereas foliar sulphur application had no detectable effect. In contrast, a significant interaction among factors was observed for P. chrysocephala larval infestation. The combination of companion planting and a resistant variety resulted in significantly fewer larvae compared to the susceptible variety grown in monoculture. Sulphur treatments showed inconsistent and contrasting effects depending on the combination of other factors. Further analysis of glucosinolate profiles and plant nutritional status is expected to clarify these results. Overall, the reduction of pest incidence by varietal resistance and companion planting is confirmed. However, foliar sulphur application, or its modulation as a soil-applied fertilizer, did not produce a strong or consistent effect on pest colonization or damage. A second year of experimentation will be necessary to confirm these findings.