Coronary neovascularisation is a known phenomenon in cases of collateral formation. But the same entity has also been seen but less described in a chronic thrombus or tumors formed in atrial chambers. Here we present interesting images where neovascularisation with fistula formation was evident on angiography into a left atrial thrombus which was documented on echocardiography and also intraoperatively. This phenomenon might explain and avoid unusual anxiety when noted on angiography for the first time.