Conwy topped the list for the cleanest county in Wales
Streets in Cardiff and Blaenau Gwent have the worst litter in Wales, according to Keep Wales Tidy.
Volunteers from the campaign group inspected every county in the country over the last 12 months.
They found Conwy was the cleanest area, but that Blaenau Gwent was blighted by drink waste and dog fouling and Cardiff was littered with discarded fast food.
Blaenau Gwent and Cardiff councils said they were working to improve cleanliness in their areas.
Overall, however, the group, which checked 3,464 roads, said there had been a drop in litter across Wales.
It said that only 1.9% of streets were found to be free of any litter during the 2009 survey.
But compared to the previous year, the overall cleanliness index (CI) across Wales had improved.
The most common type of litter volunteers recorded around the country was smoking related, which was found in an average of 86% of locations, the worst affected being Cardiff, Blaenau Gwent, Caerphilly and Rhondda Cynon Taf.
But, on a more positive note, the results do show a 4% decrease in the presence of smoking litter compared to the previous year.
Fourteen local authorities were shown to have cleaned up their streets, with Monmouthshire and Newport topping the list.
On the other end of the scale, the roads in Blaenau Gwent, Bridgend, Caerphilly, Cardiff, Denbighshire, Flintshire, Merthyr Tydfil andTorfaen had got worse.
Business waste, which includes headed paper, envelopes, advertising flyers and red elastic bands generally used by the Post Office, was present on an average of 18.3% of streets.
The bands were found on 21.15% of streets inMerthyr Tydfil and the lowest percentage of elastic band strewn streets were found in Conwy.
Flintshire had a 40% drop in business waste, whilst Anglesey had a 15% increase.
Dog fouling was seen to be a major problem in Blaenau Gwent but in Carmarthenshire, Ceredigion andNeath Port Talbot there was some good news as no acts of vandalism were found.
However, Ceredigion was let down by the amount of fly-posting recorded with 14% of sites affected compared to none in Monmouthshire, Anglesey and Caerphilly.
Blaenau Gwent council said the survey results coincided with the launch of a campaign to tidy up its streets.
It said extra machines, including a new cigarette clean-up vacuum, and more man power would be used to pick up litter.
A member of staff will also be emptying and cleaning all the dog bins in the county every week.
Wardens will also be issuing fixed penalty notices of £75 to anyone caught dropping litter or any dog owner not picking up after their pet.
"We're confident that with all these initiatives everyone will start to see a real difference - and we will have a positive response from local people," it said in a statement.
Cardiff council said the city was awarded five stars in the UK's Clean City awards, one of only 12 to do so.
A campaign has led to 300 tonnes of waste from student areas in the city being recycled, while fly-tipping and graffiti are also being targeted.
Tegryn Jones, chief executive for Keep Wales Tidy, said the streets would have been a lot cleaner without discarded cigarette butts.
"It's obvious that smokers do not realise that they are letting Wales down by not binning their butts and we plan to remind them of their social and legal obligations," he said.