Hydrothermal reactions of PbCO3 (or PbCl2), V2O5, and SeO2 in KOH solution or HF solution resulted in three new lead(II)-vanadium(V) mixed-metal selenites, namely, Pb4V6O16(SeO3)3(H2O) Pb2VO2(SeO3)(2)Cl (2), and PbVO2(SeO3)F (3). Compounds I and 2 are polar (space group P2(1)), whereas compound 3 is centrosymmetric (space group Pbca). Compound I displays an unusual [V6O16(SeO3)(3)](8-) anionic chain, which is composed by a 1D [V4O12](2-) anionic chain that is further decorated by dimeric [V2O6(SeO3)3](8-) units via corner-sharing. Compound 2 features two types of ID chains, a cationic [Pb2Cl](3+) chain and a [VO2(SeO3)(2)](3-) anionic chain, whereas compound 3 contains dirneric [V2O4(SeO3)(2)F-2](2-) units. The powder second-harmonic-generating (SHG) measurements indicate that compound I shows a weak SHG response of about 0.2 X KDP (KH2PO4) under 1400 nm laser radiation. Thermal stability and optical properties as well as theoretical calculations based on density functional theory methods were also performed.