Using a broad spectrum tissue culture approach, callus was initiated from cotyledons, hypocotyls, and embryos of sugarbeet. The callus was formed under a regime of differing concentrations of several organic constituents, including growth regulators. Casein hydrolysate, GA, and vitamins were found to inhibit or have no reliable affect on callus initiation from cotyledon and hypocotyl tissues. Initiation in response to auxins and cytokinins was complex due to strong interactions between these two classes of growth regulators. In general, high concentrations (10–25 mg/litre) of auxins promoted callus initiation best. However, 2,4-D was an exception, showing inhibitory effects at concentrations greater than 1 mg/litre. The effects of cytokinins were more variable, depending upon the auxin used in combination with them. Cotyledon and hypocotyl tissues either failed to exhibit an effect due to differing concentrations of cytokinins, or showed maximal callus initiation at moderate concentrations (1–10 mg/litre). High concentrations (10–25 mg/litre) of cytokinins were, in almost all cases, inhibitory.