We consider optimal impulsive control problems involving constraints on the values of the conventional control, unilateral constraints on the state trajectories, a positivity constraint on the impulsive control and general endpoint constraints on the state trajectories. Necessary conditions of optimality in the form of a generalized Pontryagin maximum principle are provided.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)