He won a gold medal at the Antwerp salon in 1894 and exhibited at the Féderation Nationale des Artistes of Belgium starting from 1897.

[3] He was awarded a gold medal at the Universal Exposition in St. Louis, the United States in 1904 for his painting Destiny and Humanity (private collection, château de Reynel, France).

[8] He also painted portraits of Franz Joseph I of Austria, Victor Emmanuel III of Italy and other monarchs as well as of prominent members of society.

[9][10] Leempoels was a member of the Société des Beaux-Arts de Paris and a correspondent of the Academy of Fine Arts of Milan.

[3] To service his international clientele and paint his society portraits on site, Jef Leempoels maintained at various times throughout his career studios in Ixelles (Brussels), Paris, New York and Buenos Aires.

[13] While he painted many society portraits he also created scenes of social realism depicting persons from the upper as well as the working classes, which show an insight into his subjects.

Leempoels updated the clothing of the two figures, reversed the couple's position and diluted the reference to the original inspiration by not showing a naked breast nursing the child.

When the painting was exhibited in 1897 at the Salon of the Société Nationale des Beaux Arts, it was described by an art critic as two portraits in one canvas of two male friends of the same age, whose "physiognomy displays average intelligence" and who hold hands as a "sign of an indissoluble communion of feeling".

The following works are in museums, but not all are on public display: “Les Éplorés / Die Weinenden / The Weeping” (Belvedère, Vienna) ; “Amitié / Amistad / Friendship" (MNBA, Buenos Aires) ; "l’Ergoteur / El Ergotista / The Critter” (MNBA, Santiago de Chile) ; “Portrait of Miss Ana-Maria Heber-Garcia” (MNAD, Montevideo) ; Self-portrait "The painter and his wife" (Broodhuis, Brussels) ; "Portrait of Mayor Adolphe Max" (Broodhuis, Brussels).