Seeds of oilseed plants that contain large amounts of oil, polysaccharides, proteins and polyphenols are not amenable to conventional RNA isolation protocols. The presence of these substances affects the quality and quantity of isolated nucleic acids. Here, a rapid and efficient RNA isolation protocol that, in contrast to other methods tested, allows high purify, integrity and yield of total RNA from seeds of sesame, corn, sunflower, flax and rapeseed was developed. The average yields of total RNA from 70 mg oil seeds ranged from 84 to 310 A mu g with A260/A280 between 1.9 and 2.08. The RNA isolated with this protocol was verified to be suitable for PCR, quantitative real-time PCR, semi-quantitative RT-PCR, cDNA synthesis and expression analysis.