Many modern classification tasks are defined in highly-dimensional feature spaces. The derivation of high-performing genetic fuzzy rule-based classification systems (GFRBCSs) in such scenarios is a non-trivial task. This paper presents a framework for increasing the performance of GFRBCSs by creating a hierarchical fuzzy rule-based classifier. The proposed system is constructed through repeated invocations to a base GFRBCS procedure, considering at each step an input space fuzzy partition of a certain granularity. The best performing rules are inserted in the hierarchical rule base and the process is repeated again, considering a thicker granularity. The employed boosting scheme guides the algorithm in creating new rules to treat uncovered or misclassified patterns, thus monotonically increasing the performance of the classifier. Extensive experimental analysis in a number of real-world high-dimensional classification tasks proves the effectiveness of the proposed approach in increasing the performance of the base classifier, maintaining its interpretability to a considerable degree. are produced, even for relatively simple classification tasks, as the reported results in Ref. 20 indicate. Moreover, the lack of any feature selection procedure intensifies the problem, resulting at the same time in fuzzy rules with a complex linguistic representation when dealing with high-dimensional problems.Another hierarchical GFRBCS (HGFRBCS) has been previously proposed in Ref. 23, considering a multi-granular FSDB. In particular, an initial pool of candidate fuzzy rules is considered, defined in fuzzy partitions with different granularities. Subsequently, a genetic rule selection procedure selects the best cooperating rules, in order to form the final rule base. Although not initially proposed as a hierarchical FRBCS, the final rule base produced by this approach is a typical HRB. The only difference lies in the creation of the fuzzy rules, which are not produced iteratively, but rather selected from the initial pool of rules. This constitutes the main drawback of the methodology, as this pool is created by evaluating all possible rules for each fuzzy partition granularity, rendering the procedure practically inapplicable for high-dimensional problems.In this paper we propose the Hierarchical Rule-based Linguistic Classifier (HiRLiC), a framework for creating HGFRBCSs, aiming at producing compact yet high-performing HRBs, particularly in high-dimensional classification tasks. The basic idea is to repeatedly invoke a rule base extraction algorithm (RBEA), each time considering a fuzzy partition of thicker granularity. Fuzzy rules that increase the HRB's performance are maintained, whereas the rest are disregarded. In order for new rules to be created in uncovered regions of the feature space, we consider a boosting scheme that penalizes previously well covered patterns, so that new valuable rules will be localized in uncovered or mixed regions of the feature space. As the basic RBEA we consider a GFRBCS from a previous contri...