Background/Objective: Methanolic extract of Hibiscus sabdariffa extract usually produces a brilliant reddish liquid and it is believed that modification of this colored liquid may have good staining effect on thin blood smear. Therefore, this study aims to examine the staining effect of modified methanolic extract of Hibiscus sabdariffa calyx on thin peripheral blood smear in other to obtain surrogates hematological stains. Materials and methods: Dried calyx of Hibiscus sabdariffa was obtained commercially from Yola. The calyces were pulverized to fine powder and 10g of the powder was soaked in 50ml of absolute methanol for 12hours to obtain methanolic extract and thereafter, equal volume of both methanolic extract and methylene blue were mixed to obtain a modified methanolic extract. pH of modified extract was determined using pH meter. The modified methanolic extract was further used to stain thin peripheral blood smear. Results: Modified methanolic extract of Hibiscus sabdariffa calyx had pH of 7.1. The extract produces a poor staining effect on erythrocyte but gave a deep blue coloration on leucocytes, while the control stains such as field stain and Leishman stain produces a normal coloration on leucocytes and a dark pink coloration with normal pallor on erythrocyte. Conclusion: Modified methanolic extract of Hibiscus sabdariffa calyx has PH of 7.1 and produces a poor staining effect on erythrocyte but impacted a deep blue coloration on nuclear lobes of leucocytes microscopically. More research to get a modified concentration and a molar equilibrium of acidic and basic components in this extract is recommended.