Indolent lymphomas are defined by their low aggressiveness at diagnosis compared with large-cell or T-cell lymphomas: small lymph nodes or blood involvement usually existing for months or years, no B symptoms, and good performance status. However, except in mucosa-associated lymphoid tissue (MALT) lymphoma, the disease is usually disseminated and this indolent presentation does not preclude a good outcome. Indolent lymphomas consist of follicular lymphoma, small lymphocytic lymphoma (SLL), lymphoplasmacytic lymphoma (LPL), marginal-zone lymphoma (MZL), and mantle-cell lymphoma (MCL) as defined in the World Health Organization (WHO) classification. A review of morphologic characteristics, clinical presentation, prognostic factors, and outcome is presented here for each of these entities. Despite the absence of good prospective or retrospective studies in the literature, some orientations for the treatment of these patients are given, as well as some ideas for future studies.