Abstract The proportion of genetic and environmental variances for fruit weight (FW), flesh thickness (FLT), flesh weight (FLW), fruit firmness (FF), seed cavity weight (SCW), total soluble solids (TSS), titratable acidity (TA), juice acidity (pH), and ascorbic acid (AA) in guava were estimated with eight genotypes, four trees per genotype, and five fruits per tree for two seasons. The variance components of the fruit traits were consisted of genotypic variance (4.2–65.1%), seasonal variance (0–61.0%), genotype by season interaction variance (2.0–17.0%), among trees within genotype variance (0–4.2%), tree by season interaction variance (0–7.4%), and among fruit within tree variance (19.0–50.7%). A high proportion of genotypic variance was found with FW, FLT, FLW, SCW, and AA indicating that genetic improvement for these traits through breeding and selection was achievable. Seasonal variance was high for pH, while among fruits within tree variance was greatest for FF, TA, and TSS. The traits which were high in either season were more difficult to improve genetically.