This case study presents an English-speaking preschooler with severely protracted phonological development (PPD) before and after two six-week blocks of intervention (36 sessions). Pre-treatment (3;8), he showed very low whole word, singleton consonant, vowel, and word shape matches. He had two major uncommon patterns: (1) higher accuracy for word-final consonants compared with word-initial (WI) and word-medial (WM); and (2) frequent substitution of onset consonants with glottals [h] or [ʔ]. Goals and treatment strategies were selected using a nonlinear phonological approach. Post-treatment, there was a notable decrease in frequency of glottal substitutions and concomitant increase in word shape, consonant, and vowel match. Pre- and post-treatment data are presented and discussed in terms of theoretical and clinical implications.