| MCSI | Molli Computer Services, Inc. | Molli计算机服务公司。 |
| MCSI | Managed Care Systems, Inc. | 管理护理系统公司。 |
| MCSI | Missionary Care Services International | 国际传教服务 |
| MCSI | MCSi, Inc. (formerly Miami Computing Supply Corporation) | MCSi，Inc.（前迈阿密计算供应公司） |
| MCSI | Mining Consulting Services, Inc. | 矿业咨询服务公司。 |
| MCSI | Motorola Cellular Services, Inc. | 摩托罗拉蜂窝服务公司。 |
| MCSI | Multi-Channel Communications Sciences Inc. | Multi-Channel Communications Sciences公司。 |
| MCSI | Microcrystalline Silicon | 微晶硅 |
| MCSI | Multi-Media Chunk Stream Identifier | 多媒体块流标识符 |
| MCSI | Multiple Capture Single Image | 多个捕获单个图像 |