The study aimed to determine factors influencing the availability of handwashing facilities at the household level in Tanzania's Mainland. The study used secondary data from the Tanzania Household Budget Survey 2017/2018. Binary logistics regression was carried out to check the influence of characteristics of the household heads which are sex, age group, marital status, education and employment status, and the household condition characteristics, which include sanitation status, household size categories, location type, and use of building on the availability of handwashing facilities at the household level. Results revealed that the sex and employment status of the household heads had no significant influence, while age group, marital status educational level, and employment status of the household head had a significant influence on the availability of handwashing facilities. With regard to household condition, characteristics, sanitation status, household size categories, location type, and use of the building had a significant influence on the availability of handwashing facilities in households at a 5% level of significance. Therefore, the availability of handwashing facilities in households is influenced by the characteristics of the household head and housing characteristics. A study recommends community behavioural change on sanitation by conducting educational campaigns to raise awareness about the importance of handwashing and proper hygiene through several ways such as home visits.