The purpose of this study was basically twofold: 1) to develop an evaluative instrument to measure interpersonal communicative competence, and 2) to determine its relationship to three other supervisory variables—demographic characteristics, self-actualization, and leader behavior. Hypotheses testing, via the Pearson correlation coefficient, indicated the following relationships between interpersonal communicative competence (as measured by the IICC) and supervisory demographics, self-actualization (as measured by the POI), and leader behavior (as measured by the SBDQ): 1) The age of the supervisor was negatively related to the IICC at the .001 level of statistical significance. 2) Years of formal education was positively related to the IICC at the .001 level. 3) The sex of the supervisor (females scoring higher) was related to the IICC at the .01 level. 4) No significant relationship existed between years of supervisory experience and the IICC. 5) Six scales of the POI (I, Ex, Fr, S, A, C) were related to the IICC at the .001 level of statistical significance, one scale (Sy) at the .01 level and two scales (Tc, Sa) at the .05 level. Three scales (SAV, Sr, Nc) were not significantly related to the IICC. 6) No significant relationship existed between the IICC and the two dimensions of leader behavior—structure and consideration.