This dissertation describes and compares the tense-aspect systems found in three southeastern Bantu languages, viz. Chichewa, Citumbuka and Cisena. For each language, an in-depth description of the tense-aspect categories and their use is given based on the analysis of different sources of data: audio recordings of arranged conversations and narratives, questionnaires in which native speakers of Chichewa, Citumbuka and Cisena translated English sentences into their own language, and parallel corpora of Biblical texts as well as direct elicitation and consultation sessions. The description provides evidence of dialectal variation in the tense-aspect systems in each language that has not been described systematically before. Furthermore, it discusses specific diachronic changes, such as the development of the present progressive marker -ku- into a present tense marker in Chichewa. Remoteness distinctions in the past and future tenses, which are common across Bantu, are also found in the three languages under investigation here. The use of these categories is studied in detail and a certain extent of flexibility in their use is observed. For some varieties of Chichewa, a remoteness distinction is even found for past imperfective forms referring to habits or continuous events in the past, a distinction that has not been described previously. Further emphasis is placed on the comparison of tense-aspect markings in negated as opposed to affirmative clauses. In all three languages, the perfect marker -a- is only found in affirmative clauses while a past tense marker or a particular form only found in clauses of this type, a negative perfect marker, occurs in the corresponding negative. The comparison of the three tense-aspect systems shows that the overall design of the systems and the distinctions that are made in the three languages are, despite certain differences, rather similar while the markers that express these distinctions differ across languages in many respects.