The study examined the causes of cassava post-harvest losses among farmers in Imo State, Nigeria. A structured questionnaire was used to obtain data  from 120 rural farmers using multistage, random and purposive sampling techniques. Data were analysed using percentage, mean and standard  deviation. Findings from the study reveal that farmers frequently used mobile phone calls/SMS as their sources of information on cassava postharvest  losses (x̄ =3.01) followed by the use of radio( x̄=2.5) The findings also revealed that farmers experienced different forms of post-harvest cassava losses at  one point or the other. Physical loss was experienced by 95.64% of the respondent, economic loss (93.8%) and monetary loss (97.7%).The causes of  cassava post-harvest losses included lack of finance ( x̄=3.56) poor storage (x̄ =3.46) pest and disease infection (x̄ =3.46) inappropriate harvesting time (x̄ =3.40) among others. Most of the causes of cassava post-harvest losses identified in the study area are serious. Cassava farmers should be granted  credit facilities and been courage to form cooperatives to help raise the funds and get facilities needed to reduce post-harvest losses.