Before the 2005 launch of the New Zealand SunSmart Schools Accreditation Programme (SSAP), 242 randomly sampled primary schools completed a mail survey about sun protection policies, practices, curriculum and environment. A 2009 follow-up included 189 (78%) and their mean Total Accreditation Score (TAS = total SSAP requirements met, range 0-12), increased by 0.8 (95% CI 0.5-1.2, P less than 0.001) from 7.8 (95% CI 7.4-8.1) to 8.6 (95% CI 8.3-8.9) with evidence changes differed between regions (P = 0.024). The 2009 mean TAS varied by region (range 7.9-9.4, unadjusted P = 0.004, adjusted P = 0.013) with no clear pattern, but likely resource allocation association. TAS of schools acknowledging input from Health Promoting Schools demonstrated a tendency towards being statistically significantly higher by 0.5 (95% CI -0.1 to 1.1, P = 0.082), but statistically significantly higher by 1.1 (95% CI 0.5-1.7, P less than 0.001) for schools acknowledging Cancer Society input. Lowest attainment was for the clothing (43%), shade (52%) and curriculum (55%) criteria. Key perceived barriers were cost, particularly of shade and limited support by parents and others. Schools which had not applied for accreditation identified lack of programme awareness and "other priorities' as barriers; further information, better resourcing and training assistance as key needs. Observed positive change justifies increased support to consolidate gains and achieve sustainable universality.