The study investigated the influence of parental socio-demographic factors on psychological adjustment among senior secondary school students in Rivers State, Nigeria. Ex-post factor research design was adopted in the study. The population of the study comprised all the 30,528 senior secondary school II (SS II) students in the 261 senior secondary schools in Rivers State, Nigeria. The sample for the study comprised 3,052 SS II students selected through the simple random sampling technique, using 10% of the population. Four research questions and four corresponding null hypotheses guided the study. Data were collected using the researcher’s constructed non-cognitive instrument of two sections titled ‘students’ Psychological Adjustment Questionnaire” (SPAQ) which was validated by experts in the area of Educational psychology and Measurement and Evaluation, University of Port Harcourt. Cronbach alpha method was used to establish the reliability of the instrument which yielded a value of .70. Data collected were analyzed using mean and standard deviation to answer the research questions while one-way ANOVA was used to test the null hypotheses at .05 level of significance. The result revealed that low income and low educational level of parents affect students’ psychological adjustment negetively. It was therefore recommended among others that government and non-governmental organizations should frequent schools in order to give scholarship to students of low parental income status in order to boost their psychological well being.