Background The duration of untreated psychosis (DUP), the period between the first onset of psychotic symptoms and treatment, has an important influence on the outcome of schizophrenia. Aims To compare the published studies of DUP in low- and middle-income (LAMI) countries with the DUP of high-income countries, and examine a possible association between DUP and per capita income. Method We used six search strategies to locate studies of the DUP from lami countries published between January 1975 and January 2008. We then examined the relationship between DUP and measures of economic activity, which was assessed using the LAMI classification of countries and gross domestic product (GDP) purchasing power parity. Results The average mean DUP in studies from LAMI countries was 125.0 weeks compared with 63.4 weeks in studies from highincome countries (P=0.012). Within the studies from LAMI countries, mean DUP fell by 6 weeks for every $1000 of GDP purchasing power parity. Conclusions There appears to be an inverse relationship between income and DUP in LAMI countries. The cost of treatment is an impediment to care and subsidised antipsychotic medication would improve the access to treatment and the outcome of psychotic illness in LAMI countries.