This study investigated the determinants and perceived health consequences of illegal crude oil refining in Rivers East Senatorial District, Nigeria. The study adopted a descriptive cross-sectional design. Eleven objectives, eleven research questions and four hypotheses guided the study. A sample of 393 respondents were drawn using a multistage sampling procedure. Data collection was done using a validated self-structured questionnaire with a Cronbach Alpha reliability coefficient of 0.792. Data analysis was done in SPSS using descriptive statistics (percentage, mean and standard deviation) and inferential statistics (z-test and ANOVA, and Post Hoc Bonferroni). It was found that poverty emerged as the most powerful driver (aggregate x̄= 3.05 ± 0.45), followed by corruption (x̄= 2.95 ± 0.50, high) and lack of knowledge (mean = 2.84 ± 0.49), with easy access to oil pipelines also rated as an important determinant (x̄= 2.74 ± 0.51), while non-implementation of MOUs was perceived as a relatively weak determinant (x̄= 2.57 ± 0.53). Perceived health consequences of ICOR were widely accepted, with an aggregate mean of 3.10 ± 0.40, especially for risks linked to harmful air pollutants, soot-related immune weakening, respiratory problems, eye symptoms, waterborne diseases and long-term conditions such as cancer and reduced life expectancy. Gender and income had a significant influence on perceived health consequences of illegal crude oil refining (p0.05). it was recommended among others that security agencies should co-create community patrols and anonymous reporting with youth associations using mapped hotspots, and body worn cameras, to deter sabotage, cut fire risk, and build trust