This paper presents a robust control design approach for current self-controlled power factor correction (PFC) boost converters. Lyapunov stability theory is applied to assess the closed-loop stability and performance under large load variations and vanishing input voltage disturbances. A differential-algebraic representation of the closed-loop system is considered to derive a convex optimization problem in terms of linear matrix inequality (LMI) constraints to tune the controller parameters. Numerical simulations demonstrate the potentials of the proposed approach for tuning current self-controlled PFC boost converters subject to large load variations.