One of the first Europeans to compete in the Indy 500 in 1913, he was the start of a racing dynasty that was continued by his son Andre and grandson Teddy, who was named Theodore after his grandfather.
A protegé of Camille Jenatzy, Theodore's love of racing was inspired by the activity in the area where he lived, the Ardennes, which was the first place to organise a circuit race.
He became one of the best known names in early GP racing. He was the Belgian agent for Daimler-Motoren-Gesellschaft and took over from Emil Jellinec's role of representing the Mercedes name in motor racing.
In 1906 he was due to drive a works entered Gregoire 70hp for the Circuit des Ardennes. But was listed as not arriving but the following year he did compete, this time in a Mercedes. However he retired on lap 6.
Pilette enter a team for the 1913 French Grand Prix but his entry was refused as only works teams were accepted. However at the 1913 Sarthe Club GP, held on August 5 at Le Mans, his team entry was accepted and he turned up with four Mercedes, two 6-cylinder 7.3-litre cars for Lautenschlager and Salzer, a 9.25-litre 4-cylinder car for Elskamp and a 8.9-litre 4-cylinder car for himself. Pilette was running in second place on the penultimate lap, when a tyre failure dropped him to third behind the two Delages of Bablot and Guyot.
In 1913 he became one of the first Europeans to race in the Indy 500. He drove a 4.1-litre Mercedes-Knight, entered by Chicago publisher E.C. Patterson. It was the smallest car of the field and having qualified 13th on the grid Pilette made just one pitstop during the whole race to finish 5th.
For the famous 1914 French GP Pilette was in the works team. However, he destroyed his gearbox before the race and though it was repaired before the start, he retired after three laps with a broken prop shaft.
He died in a road accident in 1921. He had been due to race at Brooklands in a private sweepstakes at the BARC Whitsun event on Monday May 16th 1921. The entry fee was 20 guineas (£22), with the winner taking all.
The entrants were Major R Cooper in the Fiat "Mephistopheles", Jack Hartshorne-Cooper in his Cooper-Clerget Eight, Count Louis Zborowski in Chitty Bang Bang I and Monsieur Pilette in his Mercedes.
Driving through Capellen in Luxemburg en route to Brooklands, having just picked up his race car from Stuggart, he crashed and was killed.