Aberdeen International has been rated the worst airport in Scotland for the fourth year in a row, according to a survey by consumer group Which?
Passengers cited a lack of seating, a limited range of shops and food outlets and long waits at baggage reclaim.
It was given the lowest rating of one star, with a customer score of 49%.
Aberdeen said it was "in the midst" of its terminal transformation project when the survey was undertaken, adding improvements had been made since then.
Inverness earned the highest customer score (68%) of the four Scottish airports included in the survey - despite being the smallest. Those surveyed said it "operated well" and was "pleasant" and "friendly".
Glasgow Airport achieved a customer score of 63%, with customers describing their experience there as "seamless" and "quick".
Edinburgh Airport, which handles more than 12 million passengers a year, scored 59%. However, it was rated the fourth best in the UK in the large airport category after Heathrow T5, Birmingham and Heathrow Terminal 3.
Passengers praised the airport for a lack of queues and ample seating. However, there were negative comments about the baggage reclaim service and the charges for picking up and dropping off at the airport.
Responding to the customer survey results, Aberdeen Airport said: "The airport was in the midst of the £20m terminal transformation project when the survey was undertaken, where we have since opened new retail facilities and a vastly improved security search area.
"We have invested heavily in airport improvements since we launched the project back in 2016.
"We're dedicated to improving the airport experience for our passengers, and with this in mind, we have upgraded our international and domestic baggage reclaim facilities, as well as new immigration and arrivals areas."
It added: "The feedback we've received from passengers has been overwhelmingly positive, and we are looking forward to opening some of the elements of the next phase of our terminal project in September."
Which? Travel editor Rory Boland said: "Whether it's for business or pleasure, for most Scots their trip starts when they get to the airport, but long queues and poor facilities can really put a dampener on your getaway.
"With new routes to and from Scotland launching all the time, passengers have an increasing choice over not just who they fly with but where they fly from.
"And, it's clear that some airports will need to improve or risk people taking their business elsewhere."
Nearly 800 Scottish airport users responded to the survey, which was carried out in April and May.