Race conditions in Node.js happen when two or more asynchronous operations attempt to access or modify shared data simultaneously, leading to inconsistent results. To prevent race conditions, you can implement locking mechanisms or queues to ensure that only one operation accesses the shared resource at a time. Libraries like `async-lock` provide simple locking functionality for this purpose. Alternatively, you can restructure your code to use atomic operations or leverage promises to chain asynchronous tasks in a controlled manner. Another option is to avoid shared mutable state by ensuring that each task works on its own copy of the data. By properly managing concurrent tasks, you can prevent race conditions and ensure consistent results in your application.