Using a reverse proxy, such as Nginx or Apache HTTP Server, is important for Node.js web servers due to several benefits it provides. It allows for load balancing, SSL/TLS termination, caching, and security. Load balancing helps distribute incoming requests across multiple Node.js servers for improved performance and high availability. SSL/TLS termination reduces the computational load on the Node.js server by handling secure connections at the proxy level. Caching stores static assets at the proxy level, improving response times. Security filters and blocks malicious requests before they reach the Node.js server.