With present day awareness of role and toxicity of lipid peroxides, serum levels of lipoperoxides have been investigated in forty pregnancy induced hypertension (PIH) subjects, before and after antihypertensive drug therapy, using full term normotensive patients as control. PIH subjects demonstrated highly significant elevated serum levels of lipoperoxides (mean 3.60 nmol/ml) in comparison (mean 2.15 nmol/ml) with full term normotensive subjects. At post-partum PIH subjects following antihypertensive drug therapy and becoming normotensive showed highly significant fall in serum lipoperoxide (mean level 2.27 nmol/ml). Full term normotensive subjects at post-partum also demonstrated the same pattern. However, observed levels of serum lipoperoxide in PIH subjects at post-partum even after becoming normotensive following treatment were found to be significantly elevated when compared with those of full term normotensives at post-partum (mean level 1.94 nmol/ml). It is felt that monitoring of serum lipoperoxide level can serve as one of the useful parameters in PIH subjects.