Industry weighs far more here than elsewhere in the Paris region, alongside a large number of very small firms. At the end of 2024, Yvelines had 41,914 employer establishments, 30,253 of them with one to nine employees (72.2%, against 70.6% for the region). Industry employs 73,184 people, 13.8% of salaried jobs in the département, against 6.9% across the Paris region. Most of these jobs are in large sites: 73.5% are in establishments with 100 or more employees. Next to them, 1,127 of the 1,919 industrial employer establishments have one to nine employees. Construction makes up 11.4% of employer establishments, against 10.7% for the region.

| Area | Employer establishments, end of 2024 | Share with 1 to 9 employees | Industry's share of salaried jobs | Construction's share of establishments |
|---|---|---|---|---|
| Yvelines | 41,914 | 72.2% | 13.8% | 11.4% |
| Paris region (Île-de-France) | 497,800 | 70.6% | 6.9% | 10.7% |
Source: INSEE (French national statistics office), complete file for Yvelines and complete file for Île-de-France, tables RES T1 and RES T2, published 27/08/2026, read 05/11/2026.
On the company side, 25.5% of the 119,729 businesses active in 2024 are in professional, scientific and technical activities and business support services: engineering offices, consultancies, advisory and accounting firms (same source, table DEN T3). A small manufacturer, a construction firm and a consultancy do not have the same task to hand to an agent.

