A small leak will sink a great ship.

A seemingly minor defect can cause the failure of something large or valuable when it is ignored. The image of a ship emphasizes that size and strength do not protect an enterprise from a persistent, uncorrected weakness.

The saying urges prompt attention to small problems before they spread or accumulate into serious damage. It applies broadly to organizations, plans, relationships, systems, or possessions whose stability depends on dealing with modest faults early.

Use it as a warning when someone dismisses a small flaw, expense, conflict, or procedural lapse that could grow into a larger failure. It suits practical advice about maintenance, oversight, and early intervention.