She fancied varnish and would look for the fundamentals of varnish work. She remained in Paris most of her working life. When she moved back to France, she met one of her friends Seizo, who was working in the lacquer industry. She pursued her work and exhibited in it when she was 35 years old. After that, she had moderate success in the same field.

During the First World War, Eileen Gray and her friend Seizo moved to London because they could no longer work. During this period, they entirely depended on their families for financial support. After the war ended, they returned to Paris and Eileen Gray was offered a job to decorate an apartment. She designed essentials for the house and furnished it with furniture she had designed. The designers who reviewed it recommended her innovativeness and viewed her work.

After this success, Eileen Gray opened her own gallery in Paris to exhibit and sell her work. She ensured that her work was good enough to represent her even when she was away, since she was still timid in the field. She later focused on furniture design and architecture. She designed buildings and houses for people and the furniture to be placed in the interior. She was the centre post of modern movement, and this enabled her to be recognized slowly as an architect and designer.

Eileen Gray was solitary and did not involve herself in much social activity. She then designed a new home for herself and furnished it. She continued with architectural studies while still following her career.

When the Second World War started, Eileen Gray stuck at home for one year but later was forced to move. In this incidence, she lost most of her precious possessions. After the war, she returned to Paris and stayed alone most of the time. She took her time and started working on new projects. Most of the people had started to forget about Eileen Gray's design work by this time. At around seventy years of age, she started losing her hearing and sight. At eighty, she changed an ancient hay-barn into a home over the summer season. From there, she continued with her work.

Before she died, her work was displayed in most of the exhibitions in London. Through out her career, Eileen Gray worked alone most of the time and was independent. After she died, people truly appreciated her work for what it was.

In 1968, a magazine was published about her work and was well received. After purchasing her archive, the National Museum opened a permanent exhibition concerning her work. The sales of her articles are still done up to this date.