The dissertation study aims to contribute mainly to the field of loanword phonology in general and particularly to Indonesian and its phonology that are rarely studied to date. The study investigates what consonantal and syllabic repair strategies are employed by Indonesian in adapting Arabic and Dutch loanwords, whether these adaptation strategies are phonological processes or phonetic operations, and whether participants' age, gender, and parents' first language (both parents speak Indonesian only vs. regional languages only) have any effect on loanword adaptation in Indonesian. To answer the above questions, a list of 111 Arabic and Dutch loanwords was elicited from 24 participants (divided in six groups, according to each of the above three variables). With respect to the consonantal repairs of both Arabic and Dutch consonants, it is found that they corroborate the hypotheses and principles proposed by the phonological approach (Paradis & LaCharite 1997, 2001, 2005, 2008), such as the Non-Availability Hypothesis, Category Proximity and Preservation principles, and the Threshold and Minimality principles. Concerning the syllabic repairs, they are also guided by phonology. For example, by virtue of Indonesian's bisyllabic minimality preference coupled with its restriction against complex codas, word-initial and word-final clusters of monosyllabic inputs are targeted by vowel epenthesis, whereas consonant clusters of polysyllabic inputs are simplified by consonantal deletion if they are word-final, or they remain unadapted if they are word-initial. Moreover, the location of the epenthetic vowel (medial epenthesis vs. edge epenthesis) in word-final clusters is determined by their sonority (i.e., Murray and Vennemann's (1983) syllable contact constraint). In conclusion, the above findings support the phonological stance that loanword adaptation is phonologically guided, not phonetically/perceptually motivated as claimed by the phonetic/perceptual approach (Dupoux & Peperkamp 2003, Peperkamp 2005, Peperkamp et al. 2008). With regard to the effect of the above variables, it is shown that age has a stronger and more systematic impact on the participants' elicited loanword adaptation, than do gender and parents' first language. This effect is mainly attributable to the participants' educational background, whereby Indonesian teenagers in high school are constantly exposed to a prescriptive grammar of formal Indonesian, unlike their adult counterparts. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]