This study aims to investigate Macao secondary school students’ attitudes towards the four most commonly used languages in Macao, namely, Cantonese, English, Portuguese and Putonghua. The study also aims to find out if the medium of instruction influences how students are motivated in the learning process, that is, whether they are integratively motivated or instrumentally motivated. Questionnaires were distributed to 274 students studying in a local secondary school, which divided itself into two sections according to the medium of instruction – Chinese and English, to collect their opinions on the languages. The results indicate that the students value Cantonese and English most, followed by Putonghua and Portuguese. Integrative and instrumental functions of Cantonese and English are highly valued. However, integrative motivations are not strong in learning Portuguese and Putonghua. Students consider the v advantages which proficiency in Portuguese can bring in getting a job in the government as the most significant instrumental value of Portuguese while proficiency in Putonghua is treated as an important asset in bringing concrete economic and instrumental benefits. T-tests were used in finding the relationships between medium of instruction and learning motivations. It is found that in learning English, EMI students tend to be more integratively motivated than CMI students while CMI students are more instrumentally motivated than EMI students. In learning Putonghua, EMI and CMI students are as instrumentally motivated as each other, but integrative motivations of CMI students are at higher levels. Concerning learning Portuguese, EMI students find the instrumental values of Portuguese attractive, whereas CMI students do not show strong interests on both the integrative and instrumental values of Portuguese. The study comes up with a conclusion that a relationship appears between medium of instruction and learning motivations, which is, integrative values of one particular language are likely to be more highly valued by students having that particular language as the medium of instruction.