The study investigated in-service biology teachers’ perceptions of the instructional use of smartphones equipped with Biology Mobile Learning Applications (BMLAs) in the learning of biology concepts in Nigerian senior secondary schools and the pedagogical rating of two commercially available mobile learning applications recommended for learning biology. The study utilized a descriptive survey design. Data collected were analyzed using descriptive and inferential statistics. Findings gathered revealed that the in-service biology teachers had good perceptions of the instructional use of BMLAs and that these perceptions influence their pedagogical rating and selection of mobile applications. The study also revealed that demographic variables such as gender and years of professional teaching experience do not have any significant effect on biology teachers’ perceptions of the instructional use of mobile applications and in the pedagogical rating of the BMLAs respectively. The implications of these findings for a mobile-enabled biology curriculum development were discussed extensively.