| Acronym | Meaning |
| HRMAS | High-resolution Magic-angle Spinning |
| HRMS | High Resolution Microwave Survey |
| HRMS | High Resolution Mass Spectrometry |
| HRMSI | High-Resolution Multispectral Instrument (EOS) |
| HRP | Horseradish Peroxidase |
| HRPA | Higher Random Phase Approximation |
| HRS | Hazard Ranking System |
| HRS | Hyper-Rayleigh Scattering |
| HRSEM | High Resolution Scanning Electron Microscopy |
| HRSG | Heat Recovery Steam Generator |
| HRT | Hormone Replacement Therapy |
| HRT | Hydraulic Retention Time |
| HRTEM | High Resolution Transmission Electron Microscopy |
| HRV | Heart Rate Variability |
| HRV | Human Rhinovirus |
| HRV | Human Rotavirus |
| HRXPS | High Resolution X-ray Photoelectron Spectroscopy |
| HRXRD | High Resolution X-ray Diffraction |
| HS-MR-CCSD | Hilbert Space-multireference-coupled Cluster (with) Single (and) Double (excitations) |
| HSA | Headspace Analysis |
| HSA | Hexanesulfonic Acid |
| HSA | Human Serum Albumin |
| HSA | Hyperspherical Adiabatic (for Resonances In Electron-atom Scattering. Energy Levels |
| HSAB | Hard And Soft Acids And Bases |
| HSBOW | Helical Spin Bond-order Wave |
| HSC | HAZMAT Spill Center |
| HSC | Health And Safety Commission (UK) |
| HSC | Hematopoietic Stem Cells |
| HSC | Hepatic Stellate Cells |
| HSC | High Conversion Soaker (cracking) [petroleum Viscosity-breaking] |
| HSC | Hyperspherical Coordinate (representation In Calcns. On Electron-atom Scattering) |
| HSCCC | High-speed Counter-current Chromatography |
| HSCIE | High-temperature Solid-state Catalytic Isotope Exchange |
| HSCR | Hirschsprung Disease |
| HSCT | High Speed Civil Transport (aircraft) |
| HSCT | Hematopoietic Stem Cell Transplantation |
| HSD | Hyperspherical Diabatic (wave Functions) |
| HSDB | Hazardous Substances Data Bank (NLM) |
| HSDI | High-speed Direct Injection (of Diesel Engines) |
| HSDP | Hawaiian Scientific Drilling Project |
| HSE | Health And Safety Executive |
| HSE | Heat-shock Element |
| HSEES | Hazardous Substances Emergency Events Surveillance |
| HSEOS | Hard-sphere Equation Of State |
| HSES | Hydrostatic Equilibrium System |
| HSF | Hiller-Sucher-Feinberg (equation For Calcn. Of Spin Densities And Charge Densities In Mols.) |
| HSF | Heat Shock Factors |
| HSG | Human Salivary Gland |
| HSGC | Headspace Gas Chromatography |
| HSGFET | Hybrid Suspended Gate Field Effect Transistor |