Biofuels from wood, wastes and various agricultural crops are currently quite expensive. Seed oil plants, instead, represent a relevant renewable natu ral resource for biodiesel to be used as engine fuel. In consequence, new genetic modified varieties (GMV) have been obtained by biotechnological meth ods, which offer a wide range of special oils for bio-energetic purposes. How ever, growing sunflower GMVs for biodiesel production could create a potential risk due to pollen flow from transgenic to non-transgenic varieties when grown in the same geographic areas. Presently, pollen flow analysis by DNA-based tools is expensive and time consuming, and new, cheap and rapid methods are needed. The goal of this research was to estimate pollen flow in sunflower by using a “composite” line, with a monogenic dominant marker (TT) for a high phenotypic expression of blue leaf nervure, as pollinator, and an inbred line and a cytoplasmic male sterile line (cms) as recipient plants. The obtained results suggest that cytoplasmic male sterility could be used for the analysis of sunflower pollen flow.