The peso ley 18.188, usually known as either peso or, to distinguish it from the earlier peso moneda nacional, informally as peso ley, was the currency of Argentina between January 1, 1970, and May 5, 1983. It was subdivided into 100 centavos. Its symbol was $L, sometimes $. Its name comes from law 18188 which established it, effective April 5, 1969.

The peso moneda nacional was the currency of Argentina from 5 November 1881 to 1 January 1970, the date in which the peso ley 18.188 was issued to the Argentine public. It was subdivided into 100 centavos, with the argentino worth 5 pesos. The peso was introduced to replace the Argentine peso moneda corriente at a rate of $+m⁄c 25 = m$n 1.