Wassily Kandinsky is widely regarded as one of the most prominent examples of a synaesthetic artist. However, in the scientific literature there is disagreement on the genuineness of his synaesthesia. This paper investigates whether Kandinsky had inborn synaesthesia, while acknowledging that there are also types of induced synaesthesia which he may have cultivated. As these two types of synaesthesia are seen to work additively in some synaesthetes and not to be mutually exclusive, this is not seen as an argument against the view that he was a true inborn synaesthete. Whether Kandinsky was a synaesthete is examined through a detailed study of his primary writings (e.g., On the Spiritual in Art, Point and Line to Plane, and Reminiscences), in light of the modern diagnostic criteria. The experiences described in those writings indicate that his synaesthetic perceptions were genuine and inborn and not just a theoretical endeavour. Given the genetic dimension of synaesthesia, this view is further supported by the fact that Kandinsky’s uncle Victor Kandinsky also described having synaesthetic experiences.