Introduction:Diarrhoea remains the second most serious health problem among children below five years old in Solomon Islands and is one of the leading causes of infant mortality,which caused about one in every ten children dying before the age of five years.Globally,around 6 million children (＜5 years) suffer from diarrhoea each year.Because of lack of previous studies,this study aims to assess the predictors of knowledge and practice of caregivers towards diarrhoea among under-five children in Mataniko informal settlements in Honiara,Solomon Islands,2016.Methods:This quantitative study was conducted at three randomly selected settlements in Honiara,Solomon Islands from June to July 2016.This study was conducted among both male and female caregivers who had children under five years of age,were aged 18 and over,live in Solomon Islands and were willing to participate in the study.A validated structured questionnaire was used to collect the data based on a 2-week recall of diarrhoea episodes.To avoid double-counting,each surveyed household was geo-referenced using global positioning system (GPS).The collected data were entered and analysed using SPSS (version 23.0) and descriptive and analytical statistics.P＜0.05 was considered as statistically significant.This study was approved by relevant ethical committees.Results:A total of 205 caregivers with at least one child under-five years participated in the study.The mean ages of caregivers and the under-five children were (30.7+8.2) years and (2.6+1.5) years,respectively.Among 205 caregivers,94 of them had reported that their children (＜5 years) had suffered with at least one episode of diarrhoea within the last 2 weeks prior to the survey.This gave a prevalence rate of 45.9％.The caregiver's knowledge about the causes (99.0％) and prevention (98.0％) of under-five diarrhoea was extremely high.Nevertheless,less than half had regularly practiced essential hygiene habits.The factors which appeared to be significantly associated with under-five diarrhoea were irregular hand washing (odds ratio [OR] 2.07,95％ confidence interval [CI]:1.12-3.81,P=0.020),inappropriate methods of disposing of children's fecal waste (OR 1.88,95％ CIL 1.06-3.33,P=0.030),and using the river for bathing (OR 1.83,95％ CI:1.04-3.23,P=0.036),and laundry (OR 2.17,95％ CI:1.23-3.84,P=0.008).Conclusion:Diarrhoea is a major public health problem among children below five years in Mataniko informal settlements.To address these exposures,relevant programs and projects should be designed,especially in areas like family planning,household economic allocation and political commitment.Awareness and advocacy programs on birth spacing,food hygiene and potential health risks about the river should be ongoing at the community level.