We have searched for the lepton-number violating processes B + → h − ℓ + ℓ + with h − = K − / π − and ℓ + = e + / μ + , using a sample of 471 ± 3 million B ¯¯¯ B events collected with the BABAR detector at the PEP-II e + e − collider at the SLAC National Accelerator Laboratory. We find no evidence for these decays and place 90%-confidence-level upper limits on their branching fractions B ( B + → π − e + e + ) < 2.3 × 10 − 8 , B ( B + → K − e + e + ) < 3.0 × 10 − 8 , B ( B + → π − μ + μ + ) < 10.7 × 10 − 8 , and B ( B + → K − μ + μ + ) < 6.7 × 10 − 8 .