The hydrotropic effect of different alkyl polyglucosides (APG) has been studied and compared with a model hydrotrope, toluol-4-sulfonic acid. The effect has been assessed by two different methods: (i) as the cloud point elevation of a solution containing different nonionic surfactants upon addition of the hydrotrope and (ii) the destabilization of liquid crystalline phases in a ternary system. The effect of the hydrophobic alkyl group length was found to be opposite in the two methods. APG with intermediate alkyl chain lengths (octyl and decyl) was shown to be very effective in elevating the cloud point, while APG with a short (butyl) group was the most efficient in destabilizing liquid crystalline phases in the system of water, sodium dodecyl sulfate and pentanol. Effects on phase behavior and cloud point elevation with addition of an APG are highly dependent on its structure. However, the correlation between structural effects as observed in the two methods requires further study. JSD 1, 485-489 (1998).