Faltings’ theorem states that there are finitely many rational points on a nice projective curve defined over the rationals of genus at least 2. The quadratic Chabauty method makes explicit some cases of Faltings’ theorem. Quadratic Chabauty has recent notable success in determining the rational points of some modular curves. In this talk, I will explain how we can leverage information from p-adic Gross–Zagier formulas to give a new quadratic Chabauty method for certain modular curves. Gross–Zagier formulas relate analytic quantities (special values of p-adic L-functions) to invariants of algebraic cycles (the p-adic height and logarithm of Heegner points). By using p-adic Gross–Zagier formulas, this new quadratic Chabauty method makes essential use of modular forms to determine rational points.