| ALT | ALOTAU | 阿罗陶 |
| ALT | Accelerate life test | 加速寿命测试 |
| ALT | alanine amiotransferase | 丙氨酸氨基转移酶 |
| ALT | Automatic Link Transfer | 自动链路转移 |
| ALT | Algorithmic Learning Theory | 算法学习理论 |
| ALT | Automatic Line Test | 自动线路测试 |
| ALT | Alternator | 交流发电机 |
| ALT | Altertue | 转路 |
| ALT | Alternate | 交流，改变 |
| ALT | Association Leadership Team | 协会领导团队 |
| ALT | Association for Learning Technology | 学习技术协会 |
| ALT | Associazione Italiana per la Lotta Alla Trombosi | Lotta Alla Trombosi意大利协会 |
| ALT | Association for Local Telecommunications | 地方电信协会 |
| ALT | Association for Linguistic Typology | 语言类型学协会 |
| ALT | Achievement Level Tests | 成就水平测试 |
| ALT | ALanine Transaminase (SGPT) | 丙氨酸转氨酶（SGPT） |
| ALT | Assistant Language Teachers | 助理语言教师 |
| ALT | Assembly Line Type | 装配线类型 |
| ALT | Abundant Larval Transcript | 丰富的幼虫转录本 |
| ALT | Accelerated Life Testing | 加速寿命试验 |
| ALT | Amarillo Little Theatre (Amarillo, TX) | 阿马里洛小剧院（德克萨斯州阿马里洛） |
| ALT | Altus AFB (Altus, OK) | Altus AFB（Altus，OK） |
| ALT | Anti Leech Tracker | 防水蛭跟踪器 |
| ALT | Automatic Line Thresholded | 自动线条阈值 |
| ALT | Advanced Lightning Technology | 先进的闪电技术 |
| ALT | Analog Line Termination | 模拟线路终端 |
| ALT | acute laryngotracheitis | 急性喉气管炎 |
| ALT | alternative | 可供替代的 |
| ALT | Argon Laser Trabeculoplasty | 氩激光小梁成形术 |
| ALT | Alarms and Telemetry (Sprint) | 警报和遥测（Sprint） |
| ALT | activated liquid thromboplastin | 活化液体凝血活酶 |
| ALT | Algorithmic Learning Theory (Conference) | 算法学习理论（会议） |
| ALT | aminoleucine transferase | 氨基亮氨酸转移酶 |
| ALT | avian laryngotracheitis | 禽喉气管炎 |
| ALT | Anarchists, Lunatics, and Terrorists | 无政府主义者、疯子和恐怖分子 |
| ALT | WordPerfect Library Menu file | WordPerfect库菜单文件 |
| ALT | Allegheny Teledyne, Inc. (delisted) | Allegheny Teledyne，Inc.（退市） |
| ALT | Application Load Table | 应用程序加载表 |
| ALT | Alternating | 交替 |
| ALT | Assistant Language Teacher | 助理语言教师 |
| ALT | Administrative Lead Time | 行政提前时间 |
| ALT | Active Leap Technology | Active Leap技术 |
| ALT | Aer Lingus Teoranta | 爱尔兰航空公司 |
| ALT | ATM Link Termination | ATM链路终端 |
| ALT | Automatic Line Testing (Nortel) | 自动线路测试（北电） |
| ALT | Acquisition, Logistics, and Technology (US Army) | 采办、后勤和技术（美国陆军） |
| ALT | Alanine Amino Transferase (medical) | 丙氨酸氨基转移酶（医用） |
| ALT | Army Liaison Team | 陆军联络小组 |
| ALT | Alteration | 变更 |
| ALT | Alto | 阿尔托 |
| ALT | Approach and Landing Test | 进近和着陆试验 |
| ALT | Accelerated Life Test | 加速寿命试验 |
| ALT | Alternative Lengthening of Telomeres (cells) | 端粒（细胞）的交替延长 |
| ALT | Alanina Amminotrasferasi (Italy) | Alanina Amminotrasferasi（意大利） |
| ALT | All Legal Transitions | 所有法律转换 |
| ALT | Altitude | 海拔高度 |
| ALT | Alternative (USENET newsgroup prefix) | 备选（USENET新闻组前缀） |
| ALT | Radar Altimeter (SEASAT, GEOS-3) | 雷达高度表（SEASAT、GEOS-3） |
| ALT | Airborne Laser Tracker | 机载激光跟踪器 |
| ALT | Aboriginal Lands Trust (Department of Indigenous Affairs) | 土著土地信托基金（土著事务部） |
| ALT | Asynchronous Line Test | 异步线路测试 |
| ALT | Advanced Learning Technologies | 高级学习技术 |
| ALT | Anarchists, Lunatics and Terrorists (apocryphal origin of newsgroup hierarchy) | 无政府主义者、疯子和恐怖分子（新闻组层级的虚构来源） |