Attachment of a conjugate assembled from a novel fluorinated carbonic anhydrase inhibitor and rhodamine B onto dehydroabietylamine (DHA) or cyclododecylamine led to first-in-class conjugates of good cytotoxicity; thereby IC50 values (from SRB assays; employed tumor cell lines A2780, A2780Cis, A549, HT29, MCF7, and non-malignant human fibroblasts CCD18Co) between 0.2 and 0.7 μM were found. Both conjugates showed similar cytotoxic activity but the dehydroabietylamine derived conjugate outperformed its cyclododecyl analog in terms of tumor cell/non-tumor cell selectivity. Both conjugates accumulate intracellular, and the DHA conjugate was able to overcome drug resistance which is effective independent of the expression status of carbonic anhydrase IX. Display omitted •Dehydroabietylamine was converted into a sulfonamide/rhodamine B conjugate.•This conjugate was tested for cytotoxic activity with a panel of human cancer cells.•This conjugate as well as a cyclododecyl analog held IC50 < 1 μM.•Both conjugates were able to overcome drug resistance and accumulated intracellular.