This Brazilian study aimed to develop the items of the Therapist's Communication Skills Inventory - Patient Version (IHCT-P); (2) to investigate its Content Validity evidence; and (3) to investigate its psychometric properties, based on the analysis of its internal structure. The construction of the items was based on a narrative review of the literature on the subject. The preliminary version of the IHCT-P contained 40 items, divided into Verbal (n=17); Non-Verbal (n=13); and Paraverbal Skills (n=10). First, the items were analyzed by five professionals with clinical and empirical expertise. The Content Validity Coefficient (CVC) was considered adequate. After deleting three items, modifying 14 and adding two, the IHCT-P had 39 items. Subsequently, this instrument underwent an evaluation of the target audience, in order to analyze whether the items are understandable for subjects with low education. Thus, the IHCT-P was presented to 30 participants, 15 women (50%), aged between 19 and 42 years (M=28,3;SD=6,2), most with higher education (63.3%). The CVC has proved to be appropriate. The content validity in these two phases of the study resulted in the exclusion of two items, 16 were modified and two were added, totalizing 39 items. In the first exploratory factor analysis (EFA), the Hull method recommended the extraction of one factor. However, seven items did not show a substantial factor loading. Therefore, a second EFA, containing 32 items, was conducted. The instrument's internal consistency was considered adequate. This instrument can help in the therapist's self-assessment, in supervision practices and in interventions. It is hoped that this research can contribute to a broader understanding of the Therapist's Communication Skills, highlighting the role they play in the therapeutic context. It is emphasized, however, that empirical investigations are necessary, as well as further validation studies of this instrument.