RTI
- Multifunctional Information Distribution System
- RTI International
- RTI International Metals
- RTI Producciones
- Radio Taiwan International
- Radio Televisión Ichilo
- Radiodiffusion Television Ivoirienne
- Ramp travel index
- Rayleigh–Taylor instability
- Reflectance Transformation Imaging
- Relative temperature index
- Reproductive tract infection
- Resistance to interrogation
- Respiratory tract infection
- Response to intervention
- Reti Televisive Italiane
- Reverse-transcriptase inhibitor
- Right to Information Act, 2005
- Rti (Lučani)
- Run-time infrastructure (simulation)
- Rádio e Televisão Independente
- Tax returns in the United Kingdom
- Underwriters Labs