diff --git a/.changeset/fluffy-weeks-float.md b/.changeset/fluffy-weeks-float.md
new file mode 100644
index 0000000000000..cca4e2c037d11
--- /dev/null
+++ b/.changeset/fluffy-weeks-float.md
@@ -0,0 +1,5 @@
+---
+"@rocket.chat/meteor": patch
+---
+
+Fixes an error causing the server to throw an "unhandled promise rejection" when removing an agent from a department without a business hour when using `Multiple` business hours
diff --git a/apps/meteor/ee/app/livechat-enterprise/server/business-hour/Multiple.ts b/apps/meteor/ee/app/livechat-enterprise/server/business-hour/Multiple.ts
index 00f67d0d8fd00..45f19dc2eda77 100644
--- a/apps/meteor/ee/app/livechat-enterprise/server/business-hour/Multiple.ts
+++ b/apps/meteor/ee/app/livechat-enterprise/server/business-hour/Multiple.ts
@@ -157,6 +157,7 @@ export class MultipleBusinessHoursBehavior extends AbstractBusinessHourBehavior
 		if (!department || !agentsId.length) {
 			return options;
 		}
+
 		return this.handleRemoveAgentsFromDepartments(department, agentsId, options);
 	}
 
@@ -325,7 +326,7 @@ export class MultipleBusinessHoursBehavior extends AbstractBusinessHourBehavior
 
 		const [agentsWithDepartment, [agentsOfDepartment] = []] = await Promise.all([
 			LivechatDepartmentAgents.findByAgentIds(agentsIds, { projection: { agentId: 1 } }).toArray(),
-			LivechatDepartment.findAgentsByBusinessHourId(department.businessHourId).toArray(),
+			...[department?.businessHourId ? LivechatDepartment.findAgentsByBusinessHourId(department.businessHourId).toArray() : []],
 		]);
 
 		for (const agentId of agentsIds) {
diff --git a/apps/meteor/tests/end-to-end/api/livechat/10-departments.ts b/apps/meteor/tests/end-to-end/api/livechat/10-departments.ts
index 6b377674bc646..9a92b6332d92e 100644
--- a/apps/meteor/tests/end-to-end/api/livechat/10-departments.ts
+++ b/apps/meteor/tests/end-to-end/api/livechat/10-departments.ts
@@ -1,5 +1,6 @@
 import { faker } from '@faker-js/faker';
-import type { ILivechatDepartment } from '@rocket.chat/core-typings';
+import type { Credentials } from '@rocket.chat/api-client';
+import type { ILivechatDepartment, IUser } from '@rocket.chat/core-typings';
 import { expect } from 'chai';
 import { before, describe, it, after } from 'mocha';
 import type { Response } from 'supertest';
@@ -15,8 +16,9 @@ import {
 	getLivechatRoomInfo,
 } from '../../../data/livechat/rooms';
 import { createMonitor, createUnit } from '../../../data/livechat/units';
-import { restorePermissionToRoles, updatePermission, updateSetting } from '../../../data/permissions.helper';
-import { createUser, deleteUser } from '../../../data/users.helper';
+import { restorePermissionToRoles, updateEESetting, updatePermission, updateSetting } from '../../../data/permissions.helper';
+import { password } from '../../../data/user';
+import { createUser, deleteUser, login } from '../../../data/users.helper';
 import { IS_EE } from '../../../e2e/config/constants';
 
 (IS_EE ? describe.skip : describe)('LIVECHAT - Departments[CE]', () => {
@@ -919,4 +921,44 @@ import { IS_EE } from '../../../e2e/config/constants';
 				.expect(200);
 		});
 	});
+
+	describe('With multiple bussines hours', () => {
+		before(async () =>
+			Promise.all([updateEESetting('Livechat_enable_business_hours', true), updateEESetting('Livechat_business_hour_type', 'Multiple')]),
+		);
+		after(async () =>
+			Promise.all([updateEESetting('Livechat_enable_business_hours', false), updateEESetting('Livechat_business_hour_type', 'Single')]),
+		);
+
+		let testUser: { user: IUser; credentials: Credentials };
+		let testDepartment: ILivechatDepartment;
+		before(async () => {
+			const user = await createUser();
+			await createAgent(user.username);
+			const credentials3 = await login(user.username, password);
+			await makeAgentAvailable(credentials3);
+
+			testUser = {
+				user,
+				credentials: credentials3,
+			};
+		});
+
+		before(async () => {
+			testDepartment = await createDepartment([{ agentId: testUser.user._id }], `${new Date().toISOString()}-department`, true);
+		});
+
+		after(async () => {
+			await Promise.all([deleteUser(testUser.user), deleteDepartment(testDepartment._id)]);
+		});
+
+		it('should allow to remove an agent from a department when multiple business hours are enabled', async () => {
+			const res = await request
+				.post(api(`livechat/department/${testDepartment._id}/agents`))
+				.set(credentials)
+				.send({ upsert: [], remove: [{ agentId: testUser.user._id, username: testUser.user.username }] })
+				.expect(200);
+			expect(res.body).to.have.property('success', true);
+		});
+	});
 });