Line a rimmed baking sheet with waxed paper; set aside. Break semisweet chocolate into small pieces; place in a microwave-safe dish. Microwave on high in 30-second increments, stirring after each, until chocolate is just melted, about 1 minute. Remove; stir until smooth.
One at a time, roll one end of pretzel rods into melted chocolate, and, using a spoon, coat each 3/4 of the way up.
Place pretzels on prepared baking sheet. Refrigerate until set, about 15 minutes.