There is considerable interest in the specialty oils markets in modifying oilseed composition to obtain high levels of specific fatty acids. Several oilseed crops are amenable to modern techniques of gene transfer; this suggests that fatty acids now available in small quantities from undomesticated species could be produced by traditional oilseed crops. However, to do this, genes for enzymes of a poorly understood biosynthetic pathway will need to be harnessed. In this review, we discuss progress and problems in the manipulation of plant lipid composition.