The present invention provides a polyisocyanate composition comprising a modified polyisocyanate obtained by a reaction between a polyisocyanate and a polyalkylene glycol alkyl ether having a specific structure. In the polyisocyanate composition, the average number of isocyanate functional groups is 1.8 or more and 4.0 or less, the moiety derived from the polyalkylene glycol alkyl ether in the modified polyisocyanate is contained in an amount of 10 mass % or more and 18 mass % or less based on the total amount of the polyisocyanate composition, and the polydispersity index of molecular weight distribution of the moiety derived from the polyalkylene glycol alkyl ether in the modified polyisocyanate is 1.05 or more and 2.00 or less.