An audit of NHS staff in Scottish hospitals suggests they wash their hands between 70% and 80% of the time.
Hand washing can prevent the spread of MRSA
Two audits were carried out, in February and September, with specially trained employees monitoring how frequently staff washed their hands.
The first showed an overall compliance rating of 68%. That rose to 79% in the second audit.
Health Secretary Nicola Sturgeon said health boards would be expected to have hygiene levels of 90% by next year.
Hand-washing is recognised as the single most important step that can be taken to reduce transmission of infection.
Compliance rates varied across health boards, with figures in the most recent audit ranging from 59% in NHS Highland to 94% in NHS Forth valley.
The September audit showed medical staff, such as doctors, dentists and consultants, achieved a compliance rate of 62%.
Ms Sturgeon said: "More needs to be done to ensure that hand hygiene standards are as rigorous as possible.
"Patients and the public rightly expect the highest possible standards of cleanliness and hand hygiene in our hospitals to prevent the spread of infections."
The health secretary added: "Monitoring hand hygiene practices in our hospitals is an important development in our fight against infections and will ensure that we know that all health staff are employing the highest possible standards of hand hygiene."
Health boards are to be given funding for at least the next two years to help highlight the importance of good hand hygiene to health staff, patients and the public.
Claire Kilpatrick, nurse consultant infection control with Health Protection Scotland, said the improvement in compliance rates between the two audits was significant.
She said: "We are just starting to seriously address compliance as a country and overall it is already getting better.
"Many staff are working towards achieving the highest possible standards to reduce the spread of infections through good hand hygiene."
Tory health spokeswoman Mary Scanlon said the figures underlined the "urgent need for more action".
She added: "Many people will be astonished that after so much suffering, so much publicity and so many millions spent, this compliance rate is not higher."