A composition for controlling plant diseases comprising a tetrazolinone compound represented by a formula (1) : wherein n is an integer of any one of 0 to 5 R 1 represents a halogen atom and the like R 2 represents a C1-C3 alkyl group and the like the R 1 or R 2 can have independently halogen atom(s) in the alkyl moiety with the proviso that when n is an integer of 2 or more, two or more of the R 1 may be different from each other, and an azole compound, preferably the composition for controlling plant diseases wherein a weight ratio of the tetrazolinone compound to the azole compound is that of the tetrazolinone compound/the azole compound = 0.1/1 to 10/1, shows an excellent controlling efficacy on plant diseases.
