He served concurrently as Secretary of Labor and Secretary of Public Works and Transportation under President Manuel L. Quezon. As Secretary of Labor, Avelino accomplished something unprecedented in the Philippines and perhaps the world – he unified the labor unions by organizing them into two commissions: the National Commission of Labor (NCL) and the National Commission of Peasants (NCP) – and he was designated chairman of these two Commissions. To quote Manila Bulletin: "The new Secretary of Labor José Avelino became not merely the head of the Department of Labor in the government but the head of labor organization, the head of labor in fact."