Using acid soil as a cacao seedling medium limits the seedling growth due to low fertility, thus necessitating soil ameliorant treatment to improve its chemical, physical, and biological quality. This study aimed to investigate the effect of cacao husks as organic fertilizer and biochar on chemical and biological properties of seedling media and cacao seedling growth, was conducted in Soil Biotechnology Laboratory and Soil Fertility Laboratory, Bogor Agricultural University and Pakuwon Experimental Station at Indonesian Industrial and Beverage Crops Research Institute (IIBCRI), Sukabumi, from June 2014 until February 2015. Completely randomized design (CRD) was used in the factorial treatment with three factors: (1) organic fertilizer treatment (without organic fertilizer and with organic fertilizer 10% of the weight of seedling media), (2) the types of biochar (rice husk and white albizia wood), and (3) the doses of biochar (0%, 1%, 2%, 4%, 6% of the weight of seedling media), with three replications respectively. Observation was on chemical and biological properties of the soil and seedling growth. The results showed that organic fertilizer or albizia wood biochar application significantly improved C-organic and C/N ratio. Increasing the dose of biochar or organic fertilizer application raised the pH, total N, and microbes respiration, whereas without organic fertilizer was linearly able to improve total population of microbes but not the dry weight of cacao seedling. The combination of biochar and organic fertilizers increased the stem diameter and dry weight of cacao seedling.