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The presence of sterols is one of the significant features defining eukaryotes. Plants present distinct sterol biosynthetic pathways compared to metazoans as they produce multiple end-products. They use a mandatory route to convert a C₃₀ triterpene precursor 2,3-oxidosqualene into cycloartenol and other cyclopropylsterols, which are further transformed into various functional phytosterols (24-alkyl-Δ⁵-sterols). These sterol profiles vary quite a lot relatively to organs or evenmore to cell types. A combination of analytical biochemistry approaches and the characterization of biosynthetic mutants identify functional aspects of phytosterols that go beyond the role of these lipids as reinforcers of cellular membranes. Particularly, the male gametophyte in its late developmental stage, the fast elongating pollen tube, is shown to operate a truncated sterol pathway that stands as a specialization of a complex pathway in the plant life cycle. Here, we will discuss physiological implications of cyclopropylsterols and phytosterols towards a refined understanding of plant sterol biology.