He already showed his skills at sketching when he was a child. His first steps were guided by his patron Fernando Álvarez de Sotomayor.He attended courses at the Fine Arts Circle in Madrid and managed to celebrate seven exhibitions, although he was still very young.
Concheiro created drawings and watercolour pictures that can be found in the Provincial Art Gallery in A Coruña. After the period he spent in Madrid and when he returned to Galicia, Concheiro became schizophrenic. This made him create an abnormal painting with absurd characters but a great artistic value. In his drawing album (1930), his painting shows clearly his distorted imagination.