| IETS | Industrial Effluent Treatment System 
| Others |
| IETS | Industrial Energy-related Technologies and Systems
| Others |
| IETS | Inelastic Electron Tunneling Spectroscopy
| Others |
| IETS | Instituto de Estudos do Trabalho e Sociedade
| Others |
| IETS | Intelligence Exploitation and Targeting Systems
| Others |
| IETS | Interactive Electronic Technical Specification
| Others |
| IETS | Interim European Telecommunications Standard
| Others |
| IETS | International Education Training Services
| Others |
| IETS | International Education Travel Scholarship
| Others |
| IETS | International Embryo Technology Society
| Others |
| IETS | International Emerging Technology Symposium
| Others |