diff --git a/src/Netscript/WorkerScript.ts b/src/Netscript/WorkerScript.ts
index 6b99c43d5..726af7c84 100644
--- a/src/Netscript/WorkerScript.ts
+++ b/src/Netscript/WorkerScript.ts
@@ -80,6 +80,12 @@ export class WorkerScript {
      */
     output: string = "";
 
+    /**
+     * Process ID. Must be an integer. Used for efficient script
+     * killing and removal.
+     */
+    pid: number;
+
     /**
      * Script's Static RAM usage. Equivalent to underlying script's RAM usage
      */
@@ -100,10 +106,17 @@ export class WorkerScript {
      */
     serverIp: string;
 
-    constructor(runningScriptObj: RunningScript, nsFuncsGenerator?: (ws: WorkerScript) => object) {
+    constructor(runningScriptObj: RunningScript, pid: number, nsFuncsGenerator?: (ws: WorkerScript) => object) {
         this.name 			= runningScriptObj.filename;
     	this.serverIp 		= runningScriptObj.server;
 
+        const sanitizedPid = Math.round(pid);
+        if (typeof sanitizedPid !== "number" || isNaN(sanitizedPid)) {
+            throw new Error(`Invalid PID when constructing WorkerScript: ${pid}`);
+        }
+        this.pid = sanitizedPid;
+        runningScriptObj.pid = sanitizedPid;
+
         // Get the underlying script's code
         const server = AllServers[this.serverIp];
         if (server == null) {
diff --git a/src/Netscript/WorkerScripts.ts b/src/Netscript/WorkerScripts.ts
index 50515f413..58c184314 100644
--- a/src/Netscript/WorkerScripts.ts
+++ b/src/Netscript/WorkerScripts.ts
@@ -3,4 +3,4 @@
  */
 import { WorkerScript } from "./WorkerScript";
 
-export const workerScripts: WorkerScript[] = [];
+export const workerScripts: Map<number, WorkerScript> = new Map();
diff --git a/src/NetscriptWorker.js b/src/NetscriptWorker.js
index 095ba401d..cb8a355ae 100644
--- a/src/NetscriptWorker.js
+++ b/src/NetscriptWorker.js
@@ -407,6 +407,42 @@ function processNetscript1Imports(code, workerScript) {
     return res;
 }
 
+/**
+ *
+ */
+let pidCounter = 1;
+function generateNextPid() {
+    let tempCounter = pidCounter;
+
+    // Cap the number of search iterations at some arbitrary value to avoid
+    // infinite loops. We'll assume that players wont have 1mil+ running scripts
+    let found = false;
+    for (let i = 0; i < 1e6;) {
+        if (!workerScripts.has(tempCounter + i)) {
+            found = true;
+            tempCounter = tempCounter + i;
+            break;
+        }
+
+        if (i === Number.MAX_SAFE_INTEGER - 1) {
+            i = 1;
+        } else {
+            ++i;
+        }
+    }
+
+    if (found) {
+        pidCounter = tempCounter + 1;
+        if (pidCounter >= Number.MAX_SAFE_INTEGER) {
+            pidCounter = 1;
+        }
+
+        return tempCounter;
+    } else {
+        return -1;
+    }
+}
+
 /**
  * Start a script
  *
@@ -438,8 +474,17 @@ export function addWorkerScript(runningScriptObj, server) {
     }
 	server.ramUsed = roundToTwo(server.ramUsed + ramUsage);
 
+    // Get the pid
+    const pid = getNextPid();
+    if (pid === -1) {
+        throw new Error(
+            `Failed to start script because could not find available PID. This is most ` +
+            `because you have too many scripts running.`
+        );
+    }
+
 	// Create the WorkerScript
-	const s = new WorkerScript(runningScriptObj, NetscriptFunctions);
+	const s = new WorkerScript(runningScriptObj, pid, NetscriptFunctions);
 	s.ramUsage 	= ramUsage;
 
     // Start the script's execution
diff --git a/src/Script/RunningScript.ts b/src/Script/RunningScript.ts
index 59bde86b2..f3f9b617c 100644
--- a/src/Script/RunningScript.ts
+++ b/src/Script/RunningScript.ts
@@ -56,6 +56,9 @@ export class RunningScript {
     // Number of seconds that this script has been running online
     onlineRunningTime: number = 0.01;
 
+    // Process ID. Must be an integer and equals the PID of corresponding WorkerScript
+    pid: number = -1;
+
     // How much RAM this script uses for ONE thread
     ramUsage: number = 0;