diff --git a/bin/cli.js b/bin/cli.js
index 6589a7e..565818f 100755
--- a/bin/cli.js
+++ b/bin/cli.js
@@ -31,6 +31,7 @@ async function main() {
     })
     .option('-t, --timeout <timeout>', 'Timeout in milliseconds')
     .option('-k, --apiKey <apiKey>', 'OpenAI API key')
+    .option('-o, --apiOrg <apiOrg>', 'OpenAI API key')
     .option('-m, --model <model>', 'Model (gpt-3.5-turbo, gpt-4)', {
       default: 'gpt-3.5-turbo'
     })
@@ -39,6 +40,7 @@ async function main() {
       'Unique name for the conversation'
     )
     .action(async (prompt, options) => {
+      const apiOrg = options.apiOrg || process.env.OPENAI_API_ORG
       const apiKey = options.apiKey || process.env.OPENAI_API_KEY
       if (!apiKey) {
         console.error('error: either set OPENAI_API_KEY or use --apiKey\n')
@@ -71,6 +73,7 @@ async function main() {
 
       const api = new ChatGPTAPI({
         apiKey,
+        apiOrg,
         debug: options.debug,
         completionParams: {
           model
diff --git a/readme.md b/readme.md
index 655c317..1e840c1 100644
--- a/readme.md
+++ b/readme.md
@@ -150,6 +150,7 @@ Options:
   -s, --store             Enables the local message cache (default: true)
   -t, --timeout           Timeout in milliseconds
   -k, --apiKey            OpenAI API key
+  -o, --apiOrg            OpenAI API organization
   -n, --conversationName  Unique name for the conversation
   -h, --help              Display this message
   -v, --version           Display version number
diff --git a/src/chatgpt-api.ts b/src/chatgpt-api.ts
index b44cce2..3ba1619 100644
--- a/src/chatgpt-api.ts
+++ b/src/chatgpt-api.ts
@@ -16,6 +16,7 @@ const ASSISTANT_LABEL_DEFAULT = 'ChatGPT'
 export class ChatGPTAPI {
   protected _apiKey: string
   protected _apiBaseUrl: string
+  protected _apiOrg?: string
   protected _debug: boolean
 
   protected _systemMessage: string
@@ -36,6 +37,7 @@ export class ChatGPTAPI {
    * Creates a new client wrapper around OpenAI's chat completion API, mimicing the official ChatGPT webapp's functionality as closely as possible.
    *
    * @param apiKey - OpenAI API key (required).
+   * @param apiOrg - OpenAI API organization (optional).
    * @param apiBaseUrl - Optional override for the OpenAI API base URL.
    * @param debug - Optional enables logging debugging info to stdout.
    * @param completionParams - Param overrides to send to the [OpenAI chat completion API](https://platform.openai.com/docs/api-reference/chat/create). Options like `temperature` and `presence_penalty` can be tweaked to change the personality of the assistant.
@@ -49,6 +51,7 @@ export class ChatGPTAPI {
   constructor(opts: types.ChatGPTAPIOptions) {
     const {
       apiKey,
+      apiOrg,
       apiBaseUrl = 'https://api.openai.com/v1',
       debug = false,
       messageStore,
@@ -62,6 +65,7 @@ export class ChatGPTAPI {
     } = opts
 
     this._apiKey = apiKey
+    this._apiOrg = apiOrg
     this._apiBaseUrl = apiBaseUrl
     this._debug = !!debug
     this._fetch = fetch
@@ -185,6 +189,12 @@ export class ChatGPTAPI {
           stream
         }
 
+        // Support multiple organizations
+        // See https://platform.openai.com/docs/api-reference/authentication
+        if (this._apiOrg) {
+          headers['OpenAI-Organization'] = this._apiOrg
+        }
+
         if (this._debug) {
           console.log(`sendMessage (${numTokens} tokens)`, body)
         }
@@ -316,6 +326,14 @@ export class ChatGPTAPI {
     this._apiKey = apiKey
   }
 
+  get apiOrg(): string {
+    return this._apiOrg
+  }
+
+  set apiOrg(apiOrg: string) {
+    this._apiOrg = apiOrg
+  }
+
   protected async _buildMessages(text: string, opts: types.SendMessageOptions) {
     const { systemMessage = this._systemMessage } = opts
     let { parentMessageId } = opts
diff --git a/src/types.ts b/src/types.ts
index fd23cf7..84fdeea 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -10,6 +10,8 @@ export type ChatGPTAPIOptions = {
   /** @defaultValue `'https://api.openai.com'` **/
   apiBaseUrl?: string
 
+  apiOrg: string
+
   /** @defaultValue `false` **/
   debug?: boolean