Text messages could be a cost effective way of improving care for African children with malaria, according to researchers.
A six month study involving 119 health workers in Kenya, published by The Lancet, showed texts increased the number following government guidelines.
Half of children received the correct treatment at the end of the study, more than double the starting figure.
Researchers said there was "huge potential" to improve care.
There has been concern that government guidelines on malaria treatments are not always followed in the field.
Guidelines include the correct prescription of anti-malaria drugs - artemether-lumefantrine (AL) - and advice to parents.
Health workers in the study were sent text messages twice a day, five days a week, for six months.
An example of the sort of sent was: "advise mother to finish all AL doses over three days even if the child feels better after two doses".
At the beginning of the study, 20.5% of children were correctly managed, this increased to 49.6% after the six month study.
The effect appeared to persist after the texts stopped. Six months after the trial ended, 51.4% of children were receiving the correct treatment.
Professor Bob Snow, who headed the research group, said: "The role of the mobile phone in improving health providers' performance, health service management and patient adherence to new medicines across much of Africa has a huge potential."
The cost of the texts was estimated at £1.59 for the whole six months for each worker.
However, the authors acknowledge that "we do not fully understand why the intervention was successful".
They suspect it may act as a reminder or reinforce the importance of the messages in the texts.
Dr Willis Akhwale, from the Kenyan Ministry of Public Health and Sanitation, said: "We need to explore ways of scaling up such intervention to all health workers in the country."
Bruno Moonen and Justin Cohen, from the Clinton Health Access Initiative in Nairobi, said: "A combination of interventions will most likely be needed to improve adherence to national guidelines."
The study provides "strong evidence that text message reminders can be an effective, low-cost component of such a package".