Brassinosteroids are ubiquitously distributed throughout the plant kingdom sterol derivatives. Brassinosteroid deficient mutants display dramatic developmental defects including dwarfism, male sterility, delayed flowering, reduced apical dominance, and a light-grown morphology when grown in dark. Like their animal counterparts, brassinosteroids regulate the expression of numerous genes, impact the activity of complex metabolic pathways, contribute to the regulation of cell division and differentiation, and help control overall development. Brassinosteroids regulate photomorphogenesis, etiolation and cell expansion. Brassinosteroids have a broad spectrum of activities that have a positive effect on the quantity and quality of crops and they increase plant resistance to stress and pathogens.