Nidorino locations — where to catch

In Sinnoh (Diamond, Pearl & Platinum)

• Route 221 — Walk
• Valor Lakefront — Walk

In Johto & Kanto (HeartGold & SoulSilver)

• Johto Safari Zone — Walk
• Route 13 — Walk
• Route 14 — Walk
• Route 15 — Walk

In Kanto (FireRed & LeafGreen)

• Route 11 — Trade
• Safari Zone — Walk

In Johto & Kanto (Gold, Silver & Crystal)

• Route 13 — Walk
• Route 14 — Walk
• Route 15 — Walk

In Kanto (Red, Blue & Yellow)

• Celadon City — Gift
• Route 23 — Walk
• Route 9 — Walk
• Safari Zone — Walk

Other games (4)

• Brilliant Diamond / Shining Pearl (Gen 8): Route 221, Valor Lakefront
• Sword / Shield — The Isle of Armor (Gen 8): Ballimere Lake, Frigid Sea, Giant's Bed
• Let's Go, Pikachu! / Let's Go, Eevee! (Gen 7): Kanto Route 10, Kanto Route 23, Kanto Route 9
• X / Y (Gen 6): Kalos Route 11

Nidorino — full Pokédex entry