BACKGROUND: People with aphasia (PWA) frequently experience difficulties in understanding longer written content such as paragraphs or books. Reading strategies are a promising approach to treat text-level reading comprehension deficits in PWA. Nevertheless, empirical evidence for their efficacy remains rare. AIMS: The primary objective of this study was to analyse the efficacy of a strategy-based intervention on text-level reading comprehension in PWA. Secondary objectives were to compare the effects of two strategy-based intervention components and to explore potential moderator effects. METHODS & PROCEDURES: A protocol was published prior to data acquisition. In a repeated measures trial, 26 German participants with chronic, post-stroke aphasia participated in a waiting period without aphasia treatment (control condition) followed by a strategy-based intervention called 'Strategiebasierte Textverständnis-Therapie bei Aphasie' (StraTexT, 14 face-to-face-sessions, twice per week, 60 min each). Two strategy combinations, Intervention Micro targeting microstructure and Intervention Macro targeting macrostructure, were applied to newspaper and magazine articles. Participants were randomly allocated to two parallel groups that received these strategy combinations in interchanged sequences. Assessments were implemented before and after each period as well as 3 and 6 months after the intervention. The primary outcome measure was text-level reading comprehension measured with the total score of a German version of the Test de Compréhension de Textes (TCT-D). Secondary outcome measures addressed the self-reported perception of reading abilities, reading activities and feelings about reading (German version of the Comprehensive Assessment of Reading in Aphasia CARA reading questionnaire) as well as selected cognitive functions. OUTCOMES & RESULTS: The per-protocol-analysis included data from 22 participants. We found significant small improvements up to 6 months post-intervention compared to pre-intervention in the TCT-D Total (d  =  0.35-0.46) as well as medium to large improvements in the CARA questionnaire (d  =  0.68-0.96). Up to 3 months after the intervention, treatment-induced improvements in the TCT-D Total were significantly larger than change without treatment during the control condition. There was no evidence of moderator effects. Furthermore, we found improvements in several cognitive functions. CONCLUSIONS & IMPLICATIONS: Reading strategies can lead to long-term improvements in text-level reading comprehension and in self-reported reading abilities, feelings about reading and reading activities in aphasia. In regular clinical settings, it seems reasonable to implement both Intervention Micro and Intervention Macro. It remains important to investigate participant characteristics that contribute to treatment success. WHAT THIS PAPER ADDS: What is already known on the subject Systematic reviews and multiple case studies suggest that reading strategies are a promising approach to treat text-level reading comprehension in aphasia. The efficacy of reading strategies has been demonstrated for different populations. However, to date no group study has evaluated the efficacy of reading strategies on text-level reading comprehension in people with aphasia. What this study adds This study provides the first group-level evidence about the efficacy of a systematic strategy-based intervention in 22 people with post-stroke chronic aphasia. During 14 treatment sessions, participants applied four reading strategies to newspaper and magazine articles within two intervention components called Intervention Micro and Intervention Macro (two strategies per intervention component). We found improvements in text-level reading comprehension for at least 3 months post-intervention, as well as effects on selected cognitive functions and self-reported reading abilities, thoughts and feelings about reading and the ability to engage in reading activities. What are the clinical implications of this work? The strategies and materials evaluated in this study could be used in clinical practice with people with aphasia. In order to replicate treatment effects in clinical practice, we suggest applying the strategy combination with the same protocol features (e.g., frequency, duration, homework, product orientation) as in this study, implementing Intervention Micro and Intervention Macro sequentially in either order. As treatment response was not equal in all individuals, it seems important to investigate individual features that contribute to treatment success.