Design and performance of a miniature nitrogen laser with a UV preionization operating at a gas pressure from 0.25 to 1.5 atm are discussed. Effect of He, O2, and SF6 additions on the output energy and pulse repetition rate of this laser is discussed. Peak output power of 240 kW, pulse duration of 0.9 ns, and pulse repetition rate ranging from 1 to 25 Hz are demonstrated.