Where to find Quagsire in Diamond, Pearl & Platinum

Surf: Great Marsh (10%), Sinnoh Route 212 (10%, Only in Diamond & Pearl)
Walk: Great Marsh (30%, Great Marsh rotation, Before the National Dex), Sinnoh Route 212 (20%, Only in Platinum)

• Great Marsh (1) — Surf, Walk
• Route 212 — Surf, Walk

Quagsire in every game · Pokémon Diamond, Pearl & Platinum interactive map (Sinnoh)