Understanding the striatal neuronal diversity is key to decipher the basal ganglia circuit and to untangle the complex neurological and psychiatric diseases affecting this brain structure. Two main neuronal groups are found in the dorsal striatum: the abundant medium size projecting neurons (MSNs) and the local neurons or interneurons. While recent studies in the mouse striatum employing advanced technologies have unveiled a significantly broader spectrum of neuronal subtypes, it remains unclear how this diversity extends to the human brain. Here, we conducted single nuclei RNA-seq (snRNA-seq) on postmortem human caudate nucleus (CN) and putamen (Pu) samples from 28 donors to explore the diversity and abundance of neuronal populations and their underlying transcriptional structure. After analyzing about 200000 nuclei identified as neurons we defined a new striatal taxonomy with six main classes of MSNs and eight main classes of interneurons, providing their full gene-expression identity. We validated our sequencing results and investigated histological distribution and cell interactions through targeted spatial transcriptomics and quantitative FISH. Besides, we have delineated the correspondence of our classification with previous classical taxonomies and studied the main transcriptomic and class abundance differences between CN and Pu. Focusing on interneurons, we used key functional genes such as ion channels and synaptic receptors to define correspondence with the striatal mouse cell types. We have also integrated other published datasets supporting the robustness of this new classification.