Perth Prison has made "commendable progress" after serious concerns were raised over its healthcare provision, according to inspectors.
An HM Inspectorate of Prisons for Scotland (HMIPS) report gave it a "poor performance" grading for health and wellbeing following a visit last May.
Confidentiality breaches and concerns over the smoking cessation service were among the issues raised.
Inspectors returned to the prison in November to assess progress.
A report on the return visit said the prison had invested "considerable time and resource" to improve healthcare provision.
However, it said the service still has "much to do" and referred to an ongoing "critical incident', prompted by a sudden increase in prisoner numbers.
This highlighted to inspectors the "many challenges" faced by the service in being able to deliver a comprehensive healthcare service.
HM Chief Inspector of Prisons for Scotland Wendy Sinclair-Gieben said inspectors would return to HMP Perth later this year.
She said: "Commendable progress had been made in many of the areas highlighted in the full inspection report and it is testament to the partnership that the service remains committed to addressing the serious concerns raised and improving the holistic approach to healthcare provision.
"Overall, inspectors recognised that although progress had been made, the impact on patient care would not be fully visible for some time as new processes and developments bedded in."