An inhibitor for crystal growth of fats and oils, containing a polyglycerol fatty acid ester, which is an esterified product formed between a polyglycerol and a fatty acid, the polyglycerol having a hydroxyl value of 850 mg KOH/g or less and a ratio of primary hydroxyl groups to all the hydroxyl groups of the polyglycerol of 50% or more, wherein the polyglycerol fatty acid ester has a hydroxyl value of 100 mg KOH/g or less. Since the inhibitor for crystal growth of fats and oils of the present invention can inhibit crystal growth of fats and oils by adding the inhibitor to fats and oils, storage property of the fats and oils in a refrigerator, cold climates, or the like, so that the inhibitor can be suitably used in liquid fats and oils such as salad oil for which transparency is important.