We consider a k-out-of-n system in which life times of components are exponentially distributed with parameter λ/i, when there are i operational components. There is a single server who repairs the failed components. In addition, service is rendered to external customers also when there are no failed components (main customers). The external customers arrive according to a BM AP. If the arriving batch of external customers finds a free server, one among them gets into service and others, if any, move to an orbit of infinite capacity. If an arriving batch sees a busy server, the whole batch moves to the orbit. The inter-retrial times are exponentially distributed with parameter αi when there are i customers in the orbit. The external customer gets service only when the server is idle and its service is assumed to be nonpreemptive. The service times of main and external customers follow arbitrary distributions B1(· )a ndB2(·), respectively. The stability condition and steady-state distribution are obtained. Some performance measures are computed and numerical illustrations provided. In this paper we discuss the reliability of a k-out-of-n system subject to repair of failed components by a server in a retrial queue. A k-out-of-n system is characterized by the fact that the system operates as long as there are at least k operational components. We assume that the k-out-of-n system is cold. The system is cold in the sense that operational components do not fail while the system is in a down state (number of failed components at that instant is n − k + 1). Using the same analysis as employed in this paper, one can study the warm and hot systems also (a k-out-of- n system is called a hot system if operational components continue to deteriorate at the same rate while the system is down as when it is up. The system is warm if the deterioration rate while the system is up differs from that when it is down). A repair facility, consisting of a single server, repairs the failed components one at a time. The life-times of components are independent and exponentially distributed random variables with parameter λ/i when i components are operational. Thus on average, λ failures take place in unit time when the system operates with i components. The failed components are sent to the repair facility and are repaired one at a time. The waiting space has capacity to accommodate a maximum of n − k + 1 units in addition to the unit undergoing service. Service times of main customers (components of the k-out-of-n system) are independent identically distributed random variables with distribution function B1(t). In addition to repairing failed components of the system, the repair facility provides service to external customers. However these customers are entertained only when the server is idle (no component of the main system is in repair nor even waiting). These customers are not allowed to use the waiting space at the repair facility. So when external customers arrive for service (arrival process is BM AP) while the server is busy serving a component of the system or an external customer, they are directed to an orbit and try their luck after a random length of time, exponentially distributed with parameter αi when there are i customers in orbit. For a brief description of BM AP we refer to [12] and for an extensive literature survey to [3]. We stress the fact that at the instant when an external customer undergoes service if a component of the system fails, the latter’s repair starts only on completion of service of the external customer. That is, external customers are provided nonpreemptive service. The service times of external customers are independent identically distributed random variables with distribution function B2(t). Since external arrivals form a BM AP, either all in an arriving batch will proceed to an orbit on encountering a busy server or else one among the customers in the batch proceeds for service and the rest are directed to the orbit if the server is idle at that arrival epoch.