Lancashire county councillors have rejected plans for fracking company Cuadrilla to carry out seismic and pressure monitoring at a county site.
Planning officers, the Health and Safety Executive and the Environment Agency recommended approval.
But the development control committee turned down the application which had received more than 300 objections.
Later this year the county council will decide whether to give the company permission to frack at two sites.
A Cuadrilla spokesman said the company was “perplexed and disappointed” by the decision.
A spokesman for Lancashire County Council said: “The development control committee voted for the application be refused on the grounds that it considered it contrary to policies in the development plan.”