The results of a survey carried out by Recycle Western Riverside (RWR) also found that 46% of households believe that the kids are greener than the parents.
A Test the grown ups competition aimed at stimulating family discussion around recycling and getting households to think about what can be done to reduce rubbish proved a great success.
RWR education officer Damien Morris said: The Test the grown ups competition has thrown up some surprising results. Most kids believe their parents could do more to reduce the rubbish they send to landfill and in the majority of households this is the case.
Currently around a fifth of rubbish is recycled in the boroughs that took part and as about half the contents of the average household bin can be recycled, there is a lot more that can be done.
In all, 12 schools from Wandsworth, Hammersmith & Fulham and Kensington & Chelsea took part with children between seven and sixteen quizzing their parents to find out how green they really are. Cheques were awarded to the best performers, with Dolphin School of Wandsworth taking the overall prize.
Morris added: Were hoping that the competition will have a real impact on householders bins as almost 80% of participants say that as a result of taking part in the competition they have learned their lesson and will now recycle more.
The competition also included survey questions to gauge each familys perception of recycling and green issues in the household.