Farmers and landowners have safety and environment fears over an 85-mile-long high pressure gas pipe that will run from Milford Haven to Neath.
Over 100 people attended the meeting in Haverfordwest
More than 100 have met in Haverfordwest to put their concerns to Transco.
The line will pipe gas imported by sea at two terminals in Pembrokeshire to the company's UK national gas network.
Those who own land on the route will be offered compensation for disruption but Transco does have land compulsory purchase powers as a last resort.
Tuesday night's meeting was arranged by the Pembrokeshire branch of Farm Crisis Network in response to concerns from farmers and landowners.
Company officials were quizzed on the safety aspect of high pressure gas pipes including fears over construction, maintenance, potential leaks and the possibility of a terrorist attack on the line.
One of the LNG plants will be built at the Petroplus site at Milford
Nicholas Young, who farms at Rosemarket, said: "I'm concerned about my children's' future and putting a bomb in the backyard does not make me feel very good."
"I'm keeping my options open. I want to see some of the promises made in black and white."
Chartered surveyor and land agent Edward Perkins, who represented landowners along the length of the route, said there were a number of concerns but "Safety is probably top of the list at the moment".
Other concerns include potential disruption to farming while the line was being built, affect on property values and restrictions on developing land near the pipe in the future.
Assurances were also sought over the environmental impact of excavating the trench, land restoration and the impact on wildlife.
Media covering the event were only allowed to quote people with their permission but Transco officials declined to be quoted.
Transco officials spent over two hours answering questions
Instead in a statement it said it had a legal obligation to construct the pipeline to service the two Liquefied Natural Gas terminals being built at Milford Haven.
"Safety is paramount to Transco in every aspect of the project: we operate under very strict environmental and safety controls and ensure all our contractors to do the same," said the statement.
"Transco is undertaking a wide consultation process prior to construction and is committed to minimising the pipeline's impact to the landowners and tenants whose land we will cross, local communities and to the environment."
The company is aiming to start construction in the spring of 2006.